Red Alert 3 is looking pretty good. There's not a ton of information out on it but, deadline for BETA sign up is September of this year. It definitely looks like it may be a competitor (or an attempt) with SC2. I will probably end up playing both. Why? I'm a big Starcraft fan and a big C&C fan. Who will win?
RA 3 allows you to build things on water, along making that some of your units can swim, your tanks can turn into boats and vice versa, this is going to be huge.