Yeah, extremely packed. I was there last weekend. Hulk had a 90 minute wait in the afternoon. Concert area was packed.
Your only hope of having a good time is to arrive the parking garage at 07:45am, be first to the gate, take a lap around IOA, head over to USF, do Mummy and MIB using single rider line, then you can eat and slow down before the concert later that night. Concert starts around 9pm. If you really care about the concert, get there around 8pm and try to get near the front. They have gates up which make a walkway in the middle. You can slowly move forward as others leave, but it's a zoo.