Intriguingly the announcement mentions that this is the first in a three part series of games, so it could be another game set in the Warhammer Fantasy universe, or possibly one of Games Workshop's other worlds. Either way I hope they do the license justice, more justice than Warhammer Online did. Don't get me wrong, Warhammer Online had some great aspects and me and my wife played it for longer than we probably should have. We even still reminisce about our adventures through that world on occasion, but that has more to do with the setting than the gameplay.
Apparently there will be multiple playable races, from the trailer it seems at least Humans, Undead, Orks (Mine!), Dwarves (part of the human faction?), and possibly Chaos. This will be, to my knowledge, Creative Assemblies first fantasy and magic based Total War game, so it'll be interesting to see how they implement all the new systems. Well, I can't stop bouncing in my seat in excitement so I'll just leave you with a WAAAAAAAAAAGH!
And now I'm off to find a copy of Mark of Chaos and start a playthrough of Warhammer 40,000: Chaos Gate.