EC: Cooba has done some of the most creative things I've seen eyecandy-wise.
Themes: EvilMike, especially in his Resurrection series, completely nails atmosphere and theming.
Gameplay: Blur for multiplayer, EvilMike for singleplayer
Placement: Not sure what this means. Does it refer to the placement of events?
Fastest Improver: Pretty much all the up and coming level designers of this year, most of what I've seen are excellent jobs. Special props to Jimbob, though, since he seems to be the most enthused.