So after becoming more frustrated with this issue, I decided to call Apple support (Case #198189288). Worked with 2 levels of techs and they had me take it in for a logic board replacement. Did this and when I got it home, it was even worse off. I couldn't control the display at all (brightness, audio, etc). Called Apple support again (Case #198811733) and worked with a level 3 tech for a long time to troubleshoot it. Even created a new separate OS install just to make sure there wasn't a 3rd party software conflict. Didn't help.
So, took it back to the Apple store for another repair and the store manager just replaced it with a new one (how nice!) but unfortunately it has the same problem as before. 😟
I just put the laptop to sleep and re-awakened which caused the USB Audio drop out (which also locked up my iTunes for the first time) and noticed in the console log that it was having a problem with the display's internal hub and then a few seconds later, it disconnected the USB Display Audio.
1/18/11 12:38:38 PM kernel USBF: 248842.431 [0xffffff801500b600] The IOUSBFamily is having trouble enumerating a USB device that has been plugged in. It will keep retrying. (Port 4 of Hub at 0xfd130000)
1/18/11 12:38:54 PM kernel Display Audio::terminate(kIOServiceSynchronous) timeout
I used USB Prober to get the hub address just to confirm that hub is in the display.
High Speed device @ 5 (0xFD130000): ............................................. Hub device from Apple Inc.
So it seems the internal hub is having a problem reinitializing itself after a sleep. Hopefully they will determine the issue soon and release another firmware update.