GTS version of the G92, also known as the 8800 GTS 512MB, is aparently not far away according to several sources, and we're likely looking at a mid-December launch.
We doubt very much that Nvidia will officially launch this card, as it's a replacement for a current product, rather than a new product.
Nonetheless, it appears that the chips will be labeled G92-400-A2, whereas the 8800 GT is labeled G92-270-A2. Since we're looking at a slightly different feature set, this isn't that strange.
The retail pricing is meant to be around US$299-349, and these cards should outperform the current generation of 640MB GTS cards, and maybe even some of the lower clocked GTX cards, with any luck.
You can find a nice big picture of this upcoming card here