The delicate balance of resources maintained by the goddess (who limits how much metal the people of the planet have access to by sending monsters to eat people if they try to mine too much) will be exploded. Firstly because I gave the secret of safe mining to a shadowy figure in the item-maker's basements (not to mention the Dji Cantos) as part of my quest - which will allow him to start mining metals himself to sell in competition for the millenia-established miner's guild. This will prompt a pricing war between these two groups where they will each try and under-cut each other so that there'll not only be twice as much metal available to people, but it'll be half as expensive.
Secondly, because there is now an entire city's worth of metal (the carcass of the Toronto) just sitting around in the desert, ripe for the thieving.
This second factor could take things in one of a few different routes:
The Earthicans might use the Toronto's wreckage as currency with the locals to get supplies etc. (Which will provide people a much cheaper way to get metal than from mines and thus put half of Umajo Kenta out of work).
The Earthicans might use the Toronto's wreckage to build themselves a high-technology home on the planet. This would lead them to be the economic leaders of the planet, advancing the available technology of everyone around them and subsequently becoming the Americans of Albion (effectively dictating the culture of the planet even if they don't do it aggressively through force)
The Earthicans might use their weapons to take over Umajo by force.
The Earthicans might be overwhelmed by Albionians who want the metal from the Toronto for themselves (since it's extremely valuable on the planet - after all, the people of Nakiridani stripped down Tom and Hoff's podule at the start of the game almost instantly since it was so useful and they were the most scruple laden people you meet). This would lead to Umajo being armed enough for conquest.
So that's my thoughts on the economic impact of the events of the game.
How about the social impact?
Well there's no thousands of Earthicans who are trapped on the planet forever. There's no reason to expect another Toronto - it's established early on that DDT corp sunk all it's money into this mission (hence why they wanted it to pay for itself irrespective of how many cat people they have to kill). With no supply of minerals going back to earth, the company will go bust - hence no follow up ship from them. (As a side note - the outlook for earth looks pretty bleak as a result of this too. DDT is talked about as being the biggest corporation on earth - its collapse is likely to be a heavy blow to the earth economy that won't be recovered from for quite some time).
There's no reason to expect that other corporations will try and sneak in where DDT failed on Albion either. The planet is significantly further away from earth than has been standard for mining ships to attempt to reach - most likely people will say things like "Going that far out into space seems like a really bad idea - it's obviously a much bigger risk than DDT expected and we don't want to be the next mega-corp to over-reach ourselves to death".
So here's all these Earthicans trapped on a strange new world. They're not going to be happy and - despite having seen the introduction of a documentary on their vid screens about how nice the planet is - there's no reason to assume they'll be friendly with the locals. Indeed, within the Earthican group there's likely to be a lot of factioning and division. Since there's no reason for people to obey the chain of command any more, there'll probably be something of an anarchic period before leaders rise to the surface.
It's very likely that the Earthicans will fight with and kill each other over the Toronto's scrap metal as soon as a few different people notice how valuable it is to the natives.
Most of the Earthicans won't be happy to have given up the ultra-future-luxury of their space-ship life for the rustic discomfort of a planet still at 200ad technology levels.
Most Earthicans will react badly to the presence of magic.
The sudden inject of scientifically minded people into Albion's culture will degrade the don't-ask-don't-demystify culture secretly maintained by the Dji Cantos.
One of Tom, Joe or Hoff will end up telling the Earthicans about the mystical portals that can carry you around the planet. This information will then get back to the native Albionians and completly change their culture of living in one place for their whole lives and there will be a societal upheaval. Additionally - once people have learned about the portals, they'll learn about the Dji Cantos and they will DEFINITLY be un-happy. Most people, when they find out that there's a secret society governing the planet, will be resentful. Why should these people live in a luxury palace on a secret island when I have to make my living as a pig farmer on Maini? Why should be submit to being "ruled" by them (even from the shadows) instead of someone we trust (since all the places in Albion have been democratic, it's obvious that people on this world aren't keen on the idea of self appointed monarchs).
The Kenget Kamulos will have a new leader who (knowing that their deity is actually much less infalable than he expected) will want to re-exert the sect's strength (not to mention get revenge on Khunag who's killed 2 of its leaders in a row). The assassins will almost certainly take on some new venture like conquering the local Iskai and/or Human towns.
War will probably break out across the planet as the Kengets swarm out of their cave city, bad Earthicans (not all of them - just the ones who are disgruntled as a result of being trapped here and are untrusting of the locals) who want to carge a place for themselves on the planet where they live in the manner to which they are accustomed and the regular Albion people whose way of life will have been completly smashed to bits (suddenly they've got loads of machines, instant transport around the world and a secret ruling body).
Add to this the degrading of magic since the goddess's magic is diminished by scientific inquiry (as established in the story of her followers on earth - magic was real but the urge to study the world and disprove it actually stopped it working). The influx of Earthicans from a science based background will spread the ideas of studying and scepticism across the planet, diminishing or irradicating magic in the long run.
Also there will be a whole raft of plagues as the Albionians and the Earthicans give each other their diseases.
I would suggest that the story of Albion is cyclical. Just as the druids fled earth a long time ago to escape the goddess's brother, a similarly small bunch of loyal people will be driven to fleeing Albion eventually - heading to ANOTHER different planet (I'm going to all this new one Bevbeyond)
Another 2000 years later, people from Albion will probably discover space travel again. Then they'll accidentally find Bevbeyond just like the Toronto did and they'll meet the Bevbeyondians - 8-boobed dog people. Then they'll find Iskai and Humans living on this new planet too and have no idea how they got there!
My suggestion for the next game would be a straight up RPG set at this point in time, but one in which you can switch between three parties of characters - each uncovering a section of the plot in different locations.
Team 1 would be the people who go to Bevbeyond and go on a journey roughly equivalent to the one Tom & Hoff went on in Albion.
Team 2 would be another group who leave Albion and discover Earth (now no-longer capable of space travel and populated by just a few hundred people living in a ruined landscape of deserted crumbling sky-scrapers). They must discover what happened to this world (the locals probably don't even know since it will've been several generations since anyone was alive who knew what a skyscraper was for).
Team 3 will be a group who stay on Albion - now a super-technological world of wonders ruled over by a small number of mega corporations.
During the course of the game, players would explore (with their three groups of characters) how and why things ended up the way they did on Earth and Albion and then their actions would decide the fate of Bevbeyond - will you end up stranding a load of Albionians on Bevbeyond and start the whole cycle again? Will you sacrefice the lives of all the Albionians on Bevbeyond in order to safe-guard it against becomming corrupted? Will you agressivly ensure that Bevbeyond is used to feed Albion's resource needs?
I think it'd be really very exciting to play because the plot will be pretty incredibly epic PLUS you'll get to see three totally different but exciting settings.
Albion - still recognisable from the first game but only just since it is now a hustling bustling metropolis world of Iskai and Humans.
Earth - representing a horrible, crumbled glimpse of Albion's potential future if it doesn't sort itself out.
Bevbeyond - representing the lush and happy past of Albion, unspoiled and beautifully alien and exotic.
Well I'd buy it anyway...