I suggested on Geoff Keighley's blog that Microsoft should advertise Project Natal, when they release it, alongside their Netflix and on-demand movie services. Hopefully, they'll also have live TV deals by then, like they made in Britain with Sky.
People who play games infrequently, and even not at all, are already attracted to the Netflix service. I have two non-gaming relatives who use Xbox 360s exclusively for Netflix and renting movies in high definition. Consumers who own or are interested in the Wii will be attracted to Natal games. But it's a combination of both Natal gaming and cheap, on-demand movie/TV services in 360 advertising that will convert Wii owners and tap into the irregular-gamer/non-gamer market.
This leads me to a point made my Peter Molyneux about Project Natal. The new hardware, Molyneux argues, opens up possibilities beyond traditional genres and applications.
What about TV interaction? Microsoft could position their next console to become as universal as DVD players if it enables TV viewers to interact with average, non-gaming TV shows somehow.