Adding Lucasarts adventure games to Steam was a great idea, but adding classic Sierra adventure games to Steam? That's an awesome idea.
As of right now, you can buy the King's Quest Collection (which includes King's Quest I-V) and the Space Quest Collection (which includes Space Quest I-VI), both of them optimised to run on your fancy new operating system, both of them priced at $US20. Well, $US15 until July 30.
Which is good news! Know what would be better news, Valve/Activision? Quest for Glory II. Get on it.
Kotaku AU Note: These aren't available in Australia. I've pinged Activision to find out why.