Was Apple menu 'sticking' for certain dual monitor setups removed in Lion?
Here's another bit of wonky screen edge behavior in Lion.

When you activate Mission Control, your screen edges are suddenly no longer "hard" edges. Hit an edge with enough cursor velocity, and your cursor will pop through the previously cursor-bounding edge and end up on your other monitor.

This occurs on a shared screen edge between multiple monitors. My main screen (on the left) is approximately 100 pixels taller than my laptop screen (on the right). However, when I activate Misson Control and then ram my cursor exactly into the main screen's top-right corner, it then pops out into my laptop display 100 pixels below. Very annoying.

If anyone has any docs or blog posts that explain this change, please post!

I noticed this Lion behavior when developing EdgeCase.

EdgeCase might actually solve your problem. It creates hard edges that your mouse cannot cross on all shared screen edges. 

This will allow you to throw your mouse up towards the menu bar and never miss. See screenshot.