official teaser site: http://assassinscreed.uk.ubi.com/assassins-creed-2/teaser/
the information gathered so far includes the fact that you'll be playing as an Italian nobleman in Italy during the renaissance in the 1400's (roughly 300 years after the first game). You'll be aided by Leonardo DaVinci as you use dual hidden blades (OMG DUAL WIELDING!) to accomplish... whatever it is that you're trying to accomplish. Little of the plot has been revealed as of yet, other than the fact that all of this will be the product of the ancestry of Desmond whats-his-name from the first game via the animus machine. Its really confusing, especially if you haven't played the the first game.
Oh, and also, supposedly, you can swim in this installment.wikipedia page
so... anyone else already excited for this game?