Here is what I know.
Yes series three is coming out with 4 new planes. The Russian Yak-1, The US P-40E, The Japanese Ki-41, and The Italian Reggiane Re.2001 Falco.
There is a bomber expantion coming out and along with it there will be Bomber Minis of The German He 111, and The US B-25. I forget the other(s)
Each wave of planes (and bombers) has 3 different colors for a total of 12 planes per wave. Bombers may be different. The deluxe set is comprised of planes with a unique (4th) variant.
Note that in some case the different paint jobs are in fact different plane variants and the cards for the planes are slightly different.
Hope that helps.