I was on vacation and blissfully offline last week so I missed the announcement that AutoCAD 2011 for Mac Update 3 is now available in Beta (this may be old news by now but I promised I'd mention it here when it was released).
This Update introduces Lion support and resolves many of the issues currently experienced with AutoCAD 2011 for Mac running on Mac OS X Lion (10.7). Beta 1 of this update does still have some known issues so be sure and refer to the Beta readme before installing.
The project can be accessed in the AutoCAD Futures project.
All feedback should be provided in the "AutoCAD for Mac 2011 - Update 3" discussion forum.