Yeah, this all seems odd to me as well. I suppose we will have to wait, I don't know how easily someone can transfer their scripts, code, models, and stuff to another engine without breaking their work. But if something does happen...surely Crytek will have a bit of a mess on their end.
CryEngine3 is actually more advanced than the UDK while being younger. Unreal Engine 4 will have the same tech that Crytek had when they released Crysis 2 a couple of years ago. It really depends on your preference and how many features you are looking for. Unreal Engine 3 is very dated and it shows in every game that is…