I'm talking with Ben at TankGuys. Yes, 4GB Diablo's are out of stock at this moment, but Micron chips are here, and retail 4GB Diablo kits should be available later this week.
slim142, these in 2GB kits that guys are testing with new heatspreaders are D9GTR with new painted heatspreader. Still good old Microns that every overclocker wants.