They have fixed the video problem. You still need to encode to whatever the chip supports (until they get the closed drivers working on the NC that allow full resolution). But that's the same as before CM.
I think the sleep power consumption problem is not fixed. However, I have had no trouble with the battery life of my Nook Color running CM 7 release. It is snappy, pretty, and the soft-button bar at the bottom works really well. It may no go to the lowest sleep state, but at whatever state it goes to, it still lasts for days without a charge. Remember that the screen sucks down tons of power... so if that sucker is off then it doesn't drain that much power.