Word is out that the Boxee team is a few weeks away from a preliminary windows release. A small selection of Boxee users have been chosen to beta test before the release so if that goes well, I'd expect to see the Windows version open up for all Boxee users very soon.
Boxee is a HTPC software based off of the popular XB Media Center program. Boxee's popularity skyrocketed when they released their alpha version with Hulu, CBS, Comedy Central and MySpaceTV streaming built-in to the software as well as a AppleTV version of their software. The current version of Boxee supports Linux, AppleTV and Mac, but the Windows version should be here in the next few weeks.
If you already have an alpha account you can click here to download the new version.
If you want an alpha invite click here to do so.