If they aren't hypers. ASUS has a nice profile specific to those DIMMs, but I haven't seen anything spectaular yet with them. I am not too sure on how other OEMs ahve tuned BIOSes either...yet. The Hyper Era is over.
Corsair just refunded me near full retail value for my 2133MHz 2GB sticks, even, so high-speed 2GB DIMMS are a thing of the past.
What we ARE seeing is many of these new 4GB DIMMs hitting very high speeds, better than 2GB DIMMs, even. As always, things are always the best right at launch, so if you're gonna buy, now's the time to do it. With IvyBridge so close in the future, I do not expect a single silicon revision now that the platform has launched, so what you get now, CPU-wise, is probably it.
BIOSes are going to be tuned for 4 and 8 gb DIMMs, too, from what I have been hearing, so if you're buying to overclock, 4GB sticks are it.
Pre-Orders only here. I need to be able to walk into the store and get one before I'll have one. Gonna be some interesting clocking.