So, tonight in Ulduar, I tested out a little bug I had heard about where you can blink through the floor in the entrance to Freya's room. Basically, after you teleport to her room, you run forward to the middle of the lip in the doorway and then blink. It took a bunch of tries, but eventually I ended up shoulder-deep in the floor just inside her room. Then I ran forward and started falling, and falling, and falling. Then I used Slow Fall and landed in one of Yogg-Saron's nightmare rooms. Honestly nothing to do in there, and you get trapped, but it's something to do if you're bored waiting for a disconnected Shaman to come back.

Some screens of it: