Ars Technica reported on it too.
I'm definitely going to try this out since I've been sharing a Steam account with my dad since we first got the Orange Box. Well, I say 'share', but that's slightly inaccurate. Initially, his computer was the only one that was capable of playing games half decently, and he was the one with the credit card, but then I got my own computer, and Steam started allowing payments by debit card. So basically I've hijacked the account for myself to make use of the community features, while I try to keep my dad in offline mode as much as possible.
It doesn't look like it'll provide all that many benefits compared to the current situation, though. Yeah, personal saves and achievements are nice, but you still won't be able to be logged into one account with two computers, so fighting about who gets to stay online and who has to start in offline mode remains.
