Next I created a new world and started up a dwarven adventurer. Because dwarven sites on the world map are still blank, you start in a human village as usual. I walked day and night through the wilderness to get back to one of these blank sites and finally stumbled drowsily into the mountains, where it let me retire. I then created a dwarf fortress from the same civilization and waited for immigrants. It was only year 3, so without a large roster to choose from, my dwarven adventurer showed up to be a hard-working citizen... although he fell asleep on the edge of the map since it hadn't reset his drowsiness. Any dwarves from your abandoned fortresses should also show up in subsequent forts, whether originally historical or not, as long as you are with the same overall dwarven civilization.
Nice. I think this is kind of cool.
Time Scale Discussion:
I'd like to point out something here. Isn't it possible for Toady to just expand the scale. I mean you don't really need to make the game do more or less calculations, just make it so that time itself is recorded differently.
For example, making a year last twice as long can be independent of the gameplay for the most part. Right now a dwarf and a goblin can fight for three days and the same fight can take place in Adventure Mode in less than a day. So it's not like things are getting done faster in fortress mode... in fact they are happening slower based on the game world's time frame.
I think it should be pointed out that generally DF doesn't use the Timescale to calculate stuff, instead it uses the ticks unit. (To be clear, Timescale is days, month, year calculation of time used to relate to the player how much "time" has passed and ticks is how the game actually counts time. From reading the wiki Dwarves move based on ticks, so changing the Timescale will have no effect on the Dwarves moving or doing their jobs. Timescale itself is based on ticks. In fortress mode: 1 day = 1200 ticks. In adventure mode: 1 day = 86400 ticks. So a dwarf in adventure mode can do things at 72 times the speed of a dwarf in a fort in relative time.)
The biggest things influenced by Fortress mode's time scale are when the traders come, when seasons change, and when the year flips. Setting the scale to be twice as long mostly means you'd get twice as much done in a year, but migrants, trades, and possibly harvests (assuming these are linked to the timescale and not ticks) will happen less frequently. So you'll probably end up with twice as many trade goods, but have less opportunities to trade them until the caravan arc balances that.
The other problem lies in dwarves will consume twice as much food and drink in a 2x timescale due to the fact their eating and drinking habits are synced to the timescale but dependent on tick count. Though this can be changed if it is a problem (though honestly, I don't see that being a problem as it is far too easy to have surplus food and drink).
It is mostly a question of can you deal with having longer gaps between trades. It doesn't need to change anything else really, some things might be changed to make them take a more realistic time, but that is merely a possibility. It doesn't need to have any performance issues or fast-forwards because the game will still appear to run at the same speeds, the time it takes a year to pass is longer.