Yes, ATi just announced the new card, and they have some Half-Life2 flash on their site. Couple that with the fact that there's a big ass conference at Vivendi today and I think if we don't see HL2 in Sept. it will be early Nov.
And on Halo... I would buy it out of the bargain bin, you'd have to be dumb to pay premium price for this title. I'll try the demo, but the multiplayer will have to be really, REALLY, REALLY good for me to even consider purchasing.