Thanks for the reports. Just a quick summary on where we're at with the below.
OS X Lion mouse/trackpad gestures - Thanks to igngig for the helpful response on this so far! As you now know, OSX 10.7 Lion changed their default to 2-finger swipes for left/right and back/forward navigation. As igngig mentioned, you can still make 3-finger swipes work on Chrome by following his instructions, or you can set it so that 2 and 3 finger swipes do the same thing so that it won't be affected for Safari. If you're using a magic mouse, see imd23's post (thanks imd23!) on how to change this.
In the meantime however, we have been working on changing Chrome's default behavior to match the default on OSX 10.7 (tracked here: http://crbug.com/78676), and gesture support for 2-finger swiping has just been completed. It will be in an upcoming release of Chrome 14.
Fullscreen on OS X Lion - We're working on making this a great experience on Chrome as well on OS X Lion, but it's going to take more work and time. Progress on this is being tracked here: http://crbug.com/74065.