There is interesting speculation regarding the media support of Windows 8.
Windows 8 is supposed to include support for new formats, including AVC HD (with chapter seek), 3D video, and multiple MPEG-4 formats for the web, and will improve MJPEG (webcams and still cameras), MPEG-2 (decoding/encoding), H.264 (encoding), and WMV.
Additionally, speculation is, Microsoft will expand the Windows 8 Play To experiences to include HTML 5-based audio and video in web pages.
Web based TV might the new direction for Windows 8. If this works out as believed, future media PCs will not need TV tuners or the complicated software required to make them work.
To this end, Windows 8 will likely be the start of the move away from traditional TV tuners in Windows.