Maybe SOME optimization and possibly compatibility if they use them as the dev cards but outright not working? Don't think so. If that's the case, then maybe we should expect HL2 to work miracles on ATi cards but run like ass on nVidia cards right?
Well hey, who's to say there won't be BOTH of the logos on HL2? I don't have the game in front of me now and niether do you
Anyhow, you are right that it is one step too far to have it outright not working...However some optimizations ala UT2003 (aside from this AF issue) are certainly expected and tolerable.