http://pc.ign.com/articles/682/682437p1.html

It has a list of the factions, and they are as follows...

Quote Originally Posted by Bob Smith of CA
There will be 21 playable factions for custom battle and multiplayer. England, France, Scotland, Holy Roman Empire, Denmark, Spain, Portugal, Milan, Venice, Papal States, Sicily, Poland, Russia, Hungary, Byzantium, The Turks, Egypt, The Moors, The Mongols, The Tumurids, The Aztecs.

We've included several factions that weren't included in the original Medieval; examples being Scotland, Venice and Portugal.
Personally I'm a bit upset. The factions don't array for the wide possibilities that are available in certain theatres, such as the British Isles, Germany, and Iberia. In Iberia, the Aragonese/Catalan faction should be a major one. In Britain, well, I suppose England and Scotland are the only major players, but Wales was an important theatre as well. If Germany is denied, then not much will be going on in the field there besides occasional skirmishes between HRE and Poland.

To be honest, I'd like CA to work on the factions and expand on them a bit, break up Spain into Castile & Aragon, maybe add two more German factions...Hohenstraufens & Habsburgs perhaps.

Does anyone know of how the provinces will be divided up according to duchies or anything like that? IMO, CA needs to work a bit on their choice of factions.