I am able to use dual outputs successfully with the 6850.
DVI output-> HDMI adapter to TV
HDMI output -> receiver.
Desktop has to be set to extended mode.
This works correctly with 1080p content in TMT5 and in Stereoscopic Player. I do use AnyDVD though, so not sure if that has something to do with it.
(I haven't tested HD audio bitstreaming with this method yet).
Unfortunately, while this is a workaround until AMD figures its stuff out, it's a hassle because of extended desktop issues (kind of a pain to have the system think there's two displays when there's really only one), it's a hassle with the way my other components are set up, and also requires me to disconnect the secondary screen on my case (Which had been using a DVI->VGA adapter).
It does defeat the purpose of the brand new HDMI 1.4a receiver I bought in order to avoid this crap as well.
I guess moral of the story is I should've tolerated the dongle for 3D Vision -powered gaming, because this inconvenience using AMD's 'solution' is much worse.