Went to a 8:45 AM matinee yesterday. Tickets at the BO were $10.50 including 3D.
Arrived 30 minutes early expecting the early hour would limit the crowds and was correct. I managed to sit only 5 seats away from my favorite for that theater, so I was happy with my timing and not needing to wait an hour for the 9:45 to get a good seat. The showing was crowded but not sold out, only a few random viewers in front rows.
New thing I've never seen before got rolled out, usually being told to put on our 3D glasses heralds the beginning of previews but now, <SURPRISE!> a few 3D commercials were shown before previews. 
Children were present but were all very engaged in the film, and no phone light flares occurred so the big kids played nice too.