You've achieved to gather a whole lot of offtopic here, guys

I have no secret knowledge of any kind and I'm not too familiar with any official statements, but I would think that the next TW would be another one in a gunpowder age background, so they could reuse the ETW engine without changing too much. Napoleon could be a good possibility for an addon, while I'd like to see a game that begins where Medieval ends: with warfare with Pike and Musket, the Tercio, Gewalthaufen, you know what I mean. A game that would include the religious conflicts in the 16th and 17th century, namely 30 years war, and the turkish attacks on Austria could be interesting.

Aside from this speculation, I'd like to see a Shogun 2, too. The variety is not so great, because all Clans share the same culture, but I remember Shogun 1 as the vanilla game with the most authentic and thrilling atmosphere, yet.
Besides, I can't understand how anyone can not like Samurai and Ninjas

And a last point: The latest period which I could imagine in a TW game would be the american civil war, if at all. Everything later just doesn't fit anymore.