If the next TW game is going to use the RTW engine, as has been reported, I would imagine that it will be in a largely pre-gunpowder era. However, given that they have covered the ancient and medieval era, it's not obvious to me what era is left.
I hope CA don't move into fantasy, because - despite the complaints - I think they make the most fun historical wargames around. (They aim at mass market strategy games, but IMO are historical wargamers at heart and leave enough of the hardcore stuff in their games to satisfy that niche, at least after modding).
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