Mac OS X Lion works for me ok so far but the most missed feature is swiping to go back & forwardin Firefox with 2 fingers with Magic Mouse. Just Google up this page to make gesture working again in Firefox.
In short, go to Systems Preferences > Mouse.
Change “Swipe between pages” to use 2 fingers instead of the default 1 finger.
Then the “Swipe between full-screen apps” will be turned off. If not, do it manually.
Apparently this tricks works for Chrome as well.
Now I’m a happy camper again.
UPDATE: This apparently doesn’t work any more after upgraded to 10.7.1. You may have better luck with jitouch. Thanks Joe for the tip 8)