The Command & Conquer 4 multiplayer beta test will indeed be open, and it's happening today. It's scheduled for 9AM PST, which by my calculations is in about two hours. You'll want to be keep an eye over here for details.
Oh, and Battlefield: Bad Company 2 multiplayer beta is up too. Grab those keys where you can. We haven't got any, obviously, because why would we want them? Eh? EH? But our chums over at Fileplay have some, so keep an eye on them too.