I'm personally going to wait for SP2 to receive a few updates before attempting an installation. Some people are doing just fine after adding the service pack ... other's have found their system's hosed afterwards. IMHO, the best time to apply the service pack is with a fresh installation of the OS, and before adding any other applications that might not work correctly with the service pack in place.
All you can do now is either stick with SP1, or go ahead and install SP2, and hope that nothing stops working once the installation is finished. Making sure the previous system files are archived (should be an option for this during the SP2 installation), and that you have a fresh system restore point prepared in advance might be a good idea ... just in case.