As far as I can see they've only released for Ubuntu.
Not true. Valve only _supports_ ubuntu. Other distros are welcome to add steam to their package managers. For instance, Gentoo has steam in their repo. It's a thin wrapper package. When you install it, it makes sure all dependencies are met and then downloads steam from valve's server and installs it. All this is automagic as far as the user is concerned.
Which distro might that be?
At this time, there's only ~100 titles available for Linux
And a couple of weeks ago there were only 40. If they keep going at this rate things are looking promising!
Are huge TVs a US thing? I never saw a DLP TV in anyone's home, only at trade shows.
Bigger rooms, bigger TVs. I grew up in Europe before moving to the US and living rooms were much smaller than typical US living rooms. A 50" TV is pretty much the minimum around here.
Consumer Reports did a test in the mid-2000s and found about 5000 hours per bulb on average. How long that is depends on how many hours a day you keep the TV on...
Guess I got lucky. My Samsung DLP (HLN series) is from 2004. 11,000 hours on the original bulb and still works fine. Haven't had a single problem with this TV.