Apple has released MacBook Pro Retina SMC Update 1.0 to enable Power Nap support for users on Mountain Lion.
About MacBook Pro Retina SMC Update 1.0:
This update fixes several sleep/wake issues to improve the stability of MAcBook Pro with Retina display (Mid 2012) computers and is recommended for all users running OS X v10.7.4. It also enables Power Nap support for users running OS X v10.8 or later.
You can get the update by selecting Software Update from the Apple menu at the top left of your screen.
About MacBook Pro Retina SMC Update 1.0:
This update fixes several sleep/wake issues to improve the stability of MAcBook Pro with Retina display (Mid 2012) computers and is recommended for all users running OS X v10.7.4. It also enables Power Nap support for users running OS X v10.8 or later.
You can get the update by selecting Software Update from the Apple menu at the top left of your screen.