We went to Hollywood Studios yesterday on Christmas Day (only in the late afternoon and evening) and had a great time. The crowd wasn't so bad. Okay, we didn't try to do Toy Story Mania or Tower of Terror as we were mainly there for dinner, but the crowds weren't as bad as I expected.
We were able to do Star Tours on FP- (stand-by time was 40 minutes when we walked by), we did the Comedy Warehouse twice (Premier Theater was only about 50% full, so no waiting required), and we did Muppet Vision with only a 10 minute wait.
We had a reservation for Hollywood & Vine, but I overheard a CM telling a family without a reservation that the wait was about 40 minutes, which I thought wasn't so bad on Christmas Day at 7pm. Streets of America was pretty crowded at night for the Spectacle of Lights, but plenty of space to walk around.
"Sounds Dangerous" was on the map as "ABC Sound Studio - operates seasonally", and there was a screen inside showing Mickey's Christmas Carol over and over all day. There were only about 20 people in the theater when we watched it. I thought this was very nice, and I wish they would always keep this building open and show classic cartoons.