I am with you, but I am a PC gaming fan, not necessarily a Windows gaming fan. WHat I like about this is not the ability to put a Steambox into my living room, but to replace windows with SteamOS on my PC.
If I had a console with sane controls and games that fully support those controls (e.g. mouse / keyboard for first person games), I'd totally dig replacing my gaming PC with a console. Unifying your gaming PC with your living room hardware gives you a nice advantage in that you can maximize your budget for a nice HD TV / HiFi sound setup instead of buying all that stuff twice.