Well, I won't bore you with a list of what's already out there, but here are some planes we need (and have not been released yet, if they're being worked on somewhere):
Americans: P-40 Warhawk, P-47 Thunderbolt, P-38 Lightning, F4 Wildcat, F6 Hellcat, TBF Avenger (with some new torps based on the CoC ones), SBD Dauntless
UK: Hawker Hurricane, Mosquito
USSR: P-39 (dunno many Soviet planes from this era)
Germany: Me-262, Me-263, Fw-190, Bf-110
Japan: ehhhh...just finish that Zero (you know who you are) and we'll be all set : )
Whaddya think?