If the cheapest way of getting something in your living room which will play movies, stream video content from your Media Center PC, if it's the Microsoftvision, or directly off the network if it's the Sony vision, for 300 bucks, that's a lot cheaper than today's media streamers or even TiVo-like devices.
If you can, check out how Microsoft intends to deliver on this vision at the Microsoft Management Summit happening this week at the Mandalay Bay Conventions Center in Las Vegas.