I'd love some new medieval/fantasy RTS games as well. Unfortunately, there doesn't seem to be any lined up for 2012.
It's shame Stronghold 3 turned out to be such a disappointment.
Total War Shogun 2 has a stand alone expansion coming out. It's called Fall of the Samurai. I've got it on preorder already. Or the base Shogun 2 is an amazing game if you don't have it.
Total War games aren't RTS.
Well you could always get LOTR BFME2 ROTWK.
BFME2 was great, but I wouldn't recommend it to anyone now after EA shut down online gameplay. The single-player missions / skirmishes were fun, but multiplayer really made that game for me.