Upgraded to Lion and got the 10.1.1 update yesterday and my framerate is terrible. Using the low quality renderer it's really sluggish and I'm seeing lots of "junk" with things like the fog around the ground because of the world event (like something's not clipping correctly and rather than just hugging the ground I'm seeing the whole "cloud" that creates the effect). Could also be related to the hotfix and the world event as well, but wondered if it's just me.