Some ideas for mappers:
--Attack/Defend maps. Generally, these just feel better and more epic. When you know you're part of an offensive, or when you know you're assigned to hold the line, it immerses you that much more.
--A close-quarters map that actually plays slowly. Think something like Station or Apartments, with many fewer reinforcements, no artillery, a long time limit, and a loong run from spawn. A map, in effect, where you actually do have to check every corner and toss a grenade into every room.
--And this might be just me, but for those people contemplating maps in the Stalingrad setting, I think people might like to see more maps covering the August-November period.
--Ambient gunfire and artillery! Great potential there...
Man, if I just had more free time in my life and more RAM, I'd get in on this myself...