La-5
http://en.wikipedia.org/wiki/Lavochkin_La-5 , introduced in Battle for Stalingrad
http://en.wikipedia.org/wiki/Battle_of_Stalingrad .
I guess the plan is to cover one huge battle per year. For 1940 it is Battle of Britain, for 1941 - Battle for Moscow, for 1942 - Battle for Stalingrad, etc. Then come back to Western Front hopefully.
Pacific is not included I assume due to expensive royalty fees for modelling some (or all) USA aircraft.