I'm going to keep bumping this one. I think we have a good mix of mechs right now (well, okay a LOT of people are running championship Centurions, for some odd reason...), not that I wouldn't mind seeing a Zeus, Hatchetman, and/or King Crab, but I'd much rather see a glut of maps make their way into this game.
A true city map; an underwater map where everyone's slowed down, jump jets and autocannons don't work, etc; how about any of these map designs:
http://www.sarna.net/wiki/Mapsheet
And far lower priority, but it would be nice to at least be able to knock over trees or stomp cars.