I followed Tim's suggestion of removing the two compiz packages on my Mac Mini, and that did eliminate the problem of the screen going irreparably black after a few minutes of video. I still get some occasional tearing that I didn't see in 8.04.
I seem to recall some mention of a tearing fix for intel on the xorg list, which hopefully will make it downstream at some point.
I followed Tim's suggestion of removing the two compiz packages on my Mac Mini, and that did eliminate the problem of the screen going irreparably black after a few minutes of video. I still get some occasional tearing that I didn't see in 8.04.
I seem to recall some mention of a tearing fix for intel on the xorg list, which hopefully will make it downstream at some point.