From comments Steve Jobs has made elsewhere, I think that is exactly where Apple is going with this. The 802.11g wireless standard should be plenty of room for streaming wireless video to your TV. Somebody just needs to take advantage of that...
People mentioned that you needed to go back to your computer to change the song and wondered why there isn't a remote for this. When asked, Jobs just grinned and alluded to more products coming later this year. There will also be new iPods out sometime this year, hopefully this summer, which will probably work with Airport Express somehow.
goates