Adobe and Apple have worked closely together to test that Adobe® Creative Suite® 5 and CS5.5 suite editions and individual products run reliably on Intel® based systems running Mac OS X Lion (v10.7) with optimal performance and user experience. Earlier versions of Adobe Photoshop® (CS3 and CS4) software were also tested with Lion, and issues that were discovered are being documented and addressed by working closely with Apple.
See the Knowledgebase article for known issues we have discovered in our testing.
As with any new release of an operating system, there may be additional unexpected issues that arise that were not uncovered during testing. If you encounter any issues, report them on our bug report form.