I am looking forward to the day when I can come home from work, make some dinner, sit down and turn on Twitch.tv to catch "the game".
Since getting rid of my cable box I have sorely missed live sports and eSports have the potential to dig their claws in pretty deep.
Have you tried setting up a HTPC with xbmc? It's got a twitch.tv add-on that makes it easy to do exactly what you describe.
Why can't you already do that?
I already do it and it's great! Many of my favorite games are on Twitch, Starcraft, Path of Exile, League of Legends, and the best is probably Magic: the Gathering which has awesome tounament streams from StarCityGames and the Magic ProTour all day pretty much every weekend. Combined with a 52inch TV as a monitor, I have yet to plug in the cable into my TV that Comcast forces you to buy!