In field testing now with about 60 testers, maybe more.
Software still has a long way to go from what I've read. It is a special software being developed by Cybermedia (they make powerdvd IIRC) specifically for DirecTV HR2x receiver to stream to the PC.
The software uses product keys, good for only one computer. The general thought is that D* will sell this software to allow users to stream to a computer. It will only work on the local network, it is not like a slingbox.
Picture quality and sound are HD and looks good from what I've heard.