As much as I'd like to see a gloster gladiator, stuka, or b25 I think it will be another Japanese fighter (wich is prolly needed more than european planes at this moment).
I predict they will focus on early war European planes next, now that they have the early pac theater. That means we will get a Gloster Gladiator, hopefully a CR42, and an italian bomber (preffibly ones used like at malta) for a good malta scenario.
And we could get some planes like the stuka, hs-123 and other early-mid war german planes to give the Gladiator, and hurricaneI good opponents.