Oh, I know it's immature to have a wishlist, but i can't help chipping in my opinions.
Ki-84 - (and Ki-44 in the following release?)
H8K2 - It's beautiful, it's a Nipponee heavy bomber (looks to be a better bomber than the Lanc), it lands on water, what more could you ask for?
SM79 or Cant Z1007 - I don't know enough to say between these two, it would be nice to have an Italian bomber in scenarios, from the BoB to North Africa.
Pe-2 - Not only accounting for the bulk of Soviet bomber production from 1942-45, but they even made a 400+mph intercept version, one of the greats.
I-16 - nimble early war plane for variety on the Eastern front, or maybe do the I-15bis to keep the biplane nuts happy.
Mig-3 - a very fast, high alt early war fighter.
If we must have more U.S. planes:
F2A - The Brewster! With a Finnish skin. I think the case has been well made for this little plane.
P-38F - First really decent P-38 (combat flaps and 1,225 HP engines) I can't help wanting to fly my favourite plane more in the CT and scenarios.
P-39 - probably the D model (maybe Q aswell?). Default as a lendlease Soviet plane, we can always reskin it.
Oh, that's 9 already. Hmmm, for Germany, i find it hard to pick anything really new to the planeset that actually flew reliably in any quantity before the war was effectively over.
The Me-410 or He 219 would be nice interceptors, and they're both beautiful planes.
The ill fated He 177 heavy bomber, or the Ju 188, Do 17 and Do 217, even the He 111 all have a case to be made for them.
Maybe just model the Ju 52 as an alternative to the Goon.
I think what's more likely, though, is that HTC will focus on specific conflicts to fill out areas of the planeset, as they've done with the BoB and early Pac.