Apple released MacBook Air SMC Firmware Update 1.6 on Wednesday, an update that adds support for the Power Nap feature in Mountain Lion to Mid 2011 MacBook Air models.
Apple Firmware Update MAS Listing
Apple’s patch notes say, “This update enables Power Nap support on MacBook Air (Mid 2011) computers and is recommended for all users running OS X v10.8 or later.”
The update is available in the Mac App Store to Mid 2011 MacBook Air owners if they have updated to Mountain Lion. The MAS doesn’t offer a download size for the update, because apparently that’s information we no longer need. The update is also not listed on Apple’s Downloads site.