I was also under the impression that NV45 became NV40, but who knows anything anymore in this industry. :?
What seems rather clear is that NVDA cannot afford to be forced into another premature, hastily released refresh part. They need to sell a lot of NV4x chips at decent margins to recupe their huge investment (about $1 billion according to Huang) in the last two generation architectures. NV40 is looking very solid, but if doesn't cut the mustard against R420, there will be real shit hitting the fan in Santa Clara and on Wall Street.
I think the competition will be the determining factor, if ATI has a weiner then they can hold off, if ATI has a winner it maybe sooner than we may think. But then again if they lose this round they may get out of graphic chips all together