If I were the cable companies...
... I would be very nervous about this. Netflix has the possibility to create a business model where all of your video 'content' is 'on-demand'. Something that, here in the states, is a premium service that can push your cable bill up to approx US$100 per month.
I use the Netflix service, and the most annoying aspect is that only a small portion of their catalog is available for streaming. I can imagine that none of the media companies want to stream their product unless DRM can be assured (IE6-7, XP, WMP, etc...) hence the 'Windows Only' option.
Although the cable companies also deliver Internet via cable, I can imagine a time, not too far in the future, where the media compaines (VIACOM, DISNEY, etc...) give you direct access to all of their shows for a fixed or sliding fee. All categorized and targeted ads by Google, of course...