With the released of Casper Suite 8.6, OS X 10.8 Mountain Lion is now fully supported. For OTA enrollments to go smoothly on OS X 10.8, the QuickAdd package must be digitally signed with a valid Apple Developer Certificate. Without this, Gatekeeper will warn the end user that the package is not safe and prevent them from running it. You can control-click -> Open to bypass this, but this is not a good solution for end users. To make the process go smoother, Recon can sign the QuickAdd package when you generate it. This will prevent that pesky popup and make the whole OTA enrollment process go smoothly for the end user.
Check out Rich’s blog to get the details on getting a Developer ID, Digital Certificate and finally signing the QuickAdd package.Source: Der Flounder