Not sure if I can post the link, but engadget had a few reports about it.
Just google "directv vista".
Here's a snippet of what I found:
In addition to releasing Media Center PCs that can function as DirecTV receivers, Microsoft and DirecTV also promised to cooperate in several other areas, including the following:
* Future DirecTV set-top boxes will support the Windows Media Connect protocol, allowing users to connect them to a PC over a home network and then use the TV to access content from that PC, such as audio files and digital photos
* Some DirecTV boxes feature built-in digital video recording (DVR) capability; in the future, users will be able to stream recorded programs from those boxes to any Windows PC over a home network, or directly to a PMC device via a USB port
* The companies will work to integrate DirecTV and the Xbox 360 in unspecified ways; for example, users might be able to stream recorded TV content from a DirecTV DVR in one room to an Xbox 360 in another room over a home network.
Many details about the companies' agreement were left unstated: for example, it's unknown which DirecTV boxes will support PC-connected scenarios, when these boxes will be available, or what they will cost. Nonetheless, the agreement is interesting because it shows Microsoft's willingness to embrace stand-alone DVRs, rather than insisting that the Media Center PC be used for this function