AFAIK every stepping pushes production 2 months or so (charlie says). It must be the case that Nvidia currently is in the process of designing B1, or it has already been put in the oven. Which probably means that 2 or 3 months after launch we can see the B1 stepping - probably with a full GF100 with 512 SP's, and the dual GTX 470. God, this made so much sense. I think I'll apply for a CEO position at Nvidia.