Well, I don't wanna sound like a n00b or headcrab here, but judging from what Gabe said - Benchmark release on 9/30 BEFORE Half Life 2 ships , somewhat points out a delay. But I'm still optomistic about a 9/30 release!
all questions will be answered in the next 5 days. If it hasnt gone gold by then, then it's delayed. The reason we don't know whats going on is because no one knows. they are still trying to make the sept 30th dead line. Which would be awesome since the 29th is my b-day
The benchmark basically runs a demo through a bit of the game (it's not interactive, but you can watch it and ooo and ahhh) and then reports the FPS. Then you brag about how awesome your computer is and how it'll win you friends because you got (insert score here) on the HL2 demo.
Right now the benchmark is only available to members of the press. On Sept 30 apparently it'll be available the general public.