I voted for a Napoleonic TW.

I think M2TW takes us rather close to it already - with the musketeers, the cannon etc. Graphically, I think Napoleonic battles would look gorgeous on something like the M2TW engine - brightly colour uniforms, regimented units of troops, charging horses, the smoke and noise of musket volleys and cannon shot etc.

Plus, we are due a "revolutionary" TW game (like STW and RTW was) rather than an evolutionary one (like MTW and M2TW), so why not go the whole hog and move to the gunpowder era? It could also bring in sea battles, although personally it's the land warfare that really interests me.

In addition, M2TW was such a success in sticking to the "historical war" focus, and working up the RTW gameplay back to MTW standards, I think CA could do a NTW successfully. I would hate to see a half-baked "Imperial Glory 2" type affair, but I trust CA to produce a worthy successor to their own current titles.

Finally, the Napoleonic era is just absolutely perfect for a Total War game:

Strategically - you have about seven or so major powers, with lots of scope for "flexible" dipomacy and conquest. Often "conquering the map" is crazily ahistorical in history, but with Napoleon's ambitions, it becomes a pretty good representation of his historical goals. And often in history, there are strong alliances that divide up the world, Cold War style, but with Napoleon, only the enmity between Britain and France seems to have been fixed. Russia, Austria, Spain and Prussia chopped and changed with the weather.

Tactically - with the three arms of cannon, cavalry and infantry you have lots of chances for real rock-paper-scissors interactions (or even better, combined arms tactics). Personally, I hope they keep it simple like STW and not create lots of artificial distinctions like "swords vs spears" - e.g. between heavy and light infantry etc. (a man with a musket is basically a man with a musket, whatever you put as his epaulette, and Napoleonic infantry differed more in quality than in functional role).