Here's how it's gonna play out:
1. Korea. Why? Because BFC already has researched more than half the units that were in that conflict when they made the original CM games. Also, it give's them a first "shakedown" game to work out all the kinks before going to our beloved WWII setting.
2. WWII. Probabbly western front. They might start with a Normandy game and build on it from there with the expansion kits.
3. WWII again. This time a diffrent front. I prefer ostfront over all others, but many people don't, so who knows what front it will be.
4 & 5. Something else that tickels BFC's fancy that is not WWII. I'm sure those guys would like to do other wargames than WWII. Maybe modern conflicts; who knows?
6. If the engine is still around by then? Maybe back to WWII, maybe something really off the wall.
That's my guess, but what the hell do I know?