Haven't seen any, Nvidia is probably holding them back while they get the volumes up. Its easier to do that on a part like the GTX since not too many people are going to spend $600 on a video card. The midrage and lowend will be much tougher to get enough out so there won't be a shortage.
There will also be a GT and a vanilla 7800, but I haven't seen any specs on them. They'll probably use 7800 GTX cores that can't quite run at GTX speeds. I wish they'd stop trying to draw the suspence and hype out and just release the damn things. Especially if they've got a hot $300 part like ATI had with the X800 XL.
