Beaver, the Orange Box DRM is just the usual Steam app crap. Nothing spectacular, if you have Steam you already have it installed. Its not intrusive and its not broken (like EA's) in fact like Jerkk already mentioned it even has certain advantages.
However it has one big glaring problem. Security. There are a lot of trojans and viruses out there specifically designed to hack into and hijack users Steam accounts. It happened to me, and it sucks....
I have a nifty blue line!