I’ve just been told from a very, very reliable source that the G70, Nvidia’s next generation card will officially be called the 7800 (we all new that, didn’t we?). It will initially be available in three versions , the 7800 GTX, 7800 GT and 7800 and they will be launched on the 22nd of June. I've just been told the new GTX moniker will NOT replace the Ultra. An overclocked GTX will come some time after launch and this will be known as the 7800 Ultra. The Ultra may possibly be Nvidia's first 90nm part. Below is the specification for the 7800 GTX:

There was speculation that the G70 would be a 90nm part but it appears- at least at launch - that it will be built on their 110nm fabrication. I’ve also been told that SLI will only be possible with the GTX model and above. There's a neat little rumour going round that the 7800 got its name entirely down to the 3D mark 2005 score it is capable of. Take that one with a pinch of salt though. 

Power supply demands have stayed the same as far as I can tell, with a single GTX warranting 400 watts and 24 amps on the +12v rail and two GTX’s in SLI needing a 500 watt PSU and 34 amps on the +12v rail. It’s not yet clear if 512MB cards will actually be ready for launch. There is currently no word on pricing either.