I went into an end portal and I just am floating at Y=52. I've been like this for about 10 minutes. I've tried to TP myself higher and wait for me to fall back down to the ground but I just fall to Y=52 again. I still hear the sounds of the Ender Dragon and everything but nothing loads.
EDIT: I tried reloging and everything finally loaded but at first joining still nothing.
It could be that the client runs short of memory to generate the End-world, but that doesn't explain the sounds... Weird.
I don't have this issue, by the way.