My estimation is late 2013 as well... if not early till midst 2014. Okay they made huge steps forwards regarding the gfx engine, but there is still a loooot of things to do with the engine.
Besides they need to implement a couple of new planes with at least abut 5-6 NEW playable planes (there should be a vast number of AI planes, at least 20)
Apart from this they have to add a working weather system and advanced physics (TREE COLLISION!!
), and working communication. Some pilot animations (Bailout sequenze!!) are welcomed as well, maybe some of this in bombers to actually get the feeling to have a living crew in this plane and not just some dummies.
Releasing the sequel too early again would be the ende of the series. They have to release a game which fixes the great majority of bugs of CloD AND the sequel within the first release version! Anything else would be the second and last financial desaster of the company.
All these things combined are a huge amount of work and can't (or should I say shouldn't) be rushed to a release within the next 6 months.... so early 2013 is no option for me... allthough I hope for it of course. But I better wait maybe a year or two to get a bugfree sequel which has all the potential to be a financial success for the team and therefore provides us with more content in the future!