OS X Mountain Lion Limits Apps to Mac App Store, Signed Apps by Default
/Apple's identified developer program does not involve any sort of vetting on Apple's part, as certificates are automatically issued upon request and can be freely used by the developers. But what the program does do is provide a way for Apple to link specific developers to specific apps and use Gatekeeper to revoke application functionality should a developer be discovered to be distributing malware.
Sounds to me like there are no downsides. Any reputable developer can register with Apple and distribute their apps freely. But… just to be safe… let's term this one:
GATEKEEPER-GATE!
Nailed it.