Here's the bad news from Valve's Doug Lombardi:
The previously announced September 30th release date for Half-Life 2 is being pushed back. We are currently targeting a holiday release, but do not have a specific "in-store" date to share at this time. We will release that information as soon as we have confirmed a new date.
Additional commentary from the guys at
http://www.planethalflife.com:
Half-Life 2 hasn't been delayed because of NVidia, ATI, or Vivendi. So don't blame them. It hasn't been delayed because Steam isn't ready either. HL2 just needs more development time. It's no different than the original Half-Life, and I think that turned out pretty well.