I'd be honest, I find the much larger maps and the more complex mechanics of the console Fire Emblem games to be much much better than whatever Awakening has in store, though Fates is a really really refined game that gets close.
I want to see more in the vein of the Tellius games.
Fantastic music and artstyle (please bring them back, as much as I like how Fates handled both)
Triple-weapons triangle (add both Light/Dark/Anima and Wind/Fire/Thunder back)
Triple-stage class progression.
Skills system that does not require reclassing.
Massive maps with large numbers of units, and multi-stage chapters, hnnggh.
(Don't forget how Part 3 of Radiant Dawn turned out, item and unit micromanagement overkill)
But, most importantly, what happens to Ike (and Soren)?
I WON A BET AGAINST AZUREN! WOOOOOOOOOOAAAAAAAAHHHHHHHHHHHHHHHHHHH
:3
