Regardless, I know it's due to online games, but really, there should be a feature in Steam that says "Hey, he's playing an MMO, it's online only, so let's pause his current downloads unless he tells us otherwise." Or "Hey, we haven't detected any network traffic for this game after 5-10 minutes, he must be playing in offline mode, let's resume the downloads."
People aren't going to be happy when they turn on their game console and click install, then have to wait 5 hours to play a game they just purchased. Really in that case, the previous posts about power saving features really would be high priority. I get pissed off when it takes me so long to download a game that is 10GB+ (which is a large amount of games these days) and I have a 40mpbs DSL connection.
Anyhow, there are obvious pros and cons to any of these things, and I'm sure Valve has discussed them in great detail. I really think the main reason they are suddenly pushing so hard for a Linux platform (regular Steam and Console version) is simply due to them being pissed off at Microsoft (rightfully so) and their push to be like Apple.
I don't think it's out of the kindness of their hearts, or because Gabe is all of a sudden best buds with RMS or Linus.
As far as Multimedia capabilities. There is one huge gap in multimedia for Linux. It's the only other reason I use Windows AT ALL, besides games. And that is Blu-ray playback. Now if they could get the licensing for that, I'd be buying one of these steam boxes ASAP. Actually it wouldn't be a bad idea at all for Valve to start selling a blu-ray player directly through Steam that was Linux compatible. That would be awesome.
Anyhow, I'm sure it'll be a somewhat hackable device, but is going to be more geared toward the mass market, whereas any person who is into games enough more than likely already has a somewhat beefy system to play higher end games (if that is what they're into) or even a mediocre one to play emulated stuff or the simpler Humble Bundle games. The Steam console would be something like for my Brother, who is sick of the random crap that happens to (windows) computers, and so just sticks with his PS3 for games.