Good assessment from asta there on the crowds and the tour groups that are here right now.
We were at EPCOT on Saturday and they were everywhere. The park itself did not seem that busy in the morning/early afternoon though it really picked up later. The Studios on Sunday was not as busy until it got closer to the fireworks show.
It's hit or miss with the tour groups unfortunately. You can be in a park and not see one of them. Or, you can be in a park where seemingly all of them are that day.
I don't agree with huge tour groups stacking into single rider lines, but what can you do? Not sure they (Disney) should allow that, though I am not sure how to control it either.