The BBC is set to launch it's Internet TV service using Microsoft's DRM. According to the Telegraph, the player will be available tomorrow here. The beta version is supported only for Windows XP and not Vista (yet).
Controls on downloaded programs include not being able to forward or share.
The BBC iPlayer enters public beta tomorrow, and will allow licence holders to download most BBC programmes, and keep them on a computer for up to 30 days.
However, once you start watching them, you only have a seven-day period to view them, as many times as you like.