I don't play STO, but I'm opposed to some of the ideas I've read about it. I like the idea of renewed conflict with the Klingons and the Klingons annexing the Gorn and Orions, that ups the level of their badassery (something DS9 didn't do with their Klingon-Fed. War). I also liked the idea of the renegade Jem'Hadar.
Not so sure I want a war with Species 8472 (Undine), but I like the idea of the Iconians being a big bad, and I liked the conceptual look for them. I also liked the Fleet uniforms (as in the comic Countdown). As for the ship designs, I'm not too jazzed about those.