Bottomline...who really gives a fuck? The game is due out in September now, we'll have Doom 3 to play in the meantime.
If you were truly dumb enough to actually buy the 9800 for a game that wasn't even released, you deserved to be taken. Regardless, did you even read the news post a couple down on Half Life Source? They are playing with a rez of 1920x1200 on a P4 2.8C processor, 1gb DDR400, and a Radeon 9800XT. Your 9800 Pro is going to be just fine.