Q: No power nap functionality yet?

Yes, there should be a firmware update.

From http://www.apple.com/osx/whats-new/features.html:

4. Power Nap requires a Mac notebook with built-in flash storage. May require a firmware update.

Power Nap is a feature available to laptops with solid-state drives.

Best.

I know, however today is a very busy day for apple. It is possible the update is not yet ready or they just haven't gotten around to posting it yet. I think it would be wise to say it will be available pretty soon.

This will require a firmware update. Just sit tight and look for an update shortly.

Looks like only models from 2011 onwards will support power nap.

http://www.apple.com/osx/specs/

You're right - UK site also says Late 2010 models.

http://www.apple.com/uk/osx/specs/

Power Nap

Supports MacBook Air (Late 2010 or newer), MacBook Pro with Retina display.

Confusing...

Hi Everyone, now available in software update SMC Firmware Update 1.6, that update enable Power Nap in selected laptops.

Has anyone figured out if a Late 2010 MBA with SSD can get Power Nap? Some sites are saying only 2011 or newer others say you just need an SSD. I have a late 2010 13" model with SSD, hoping to have Power Nap!

The settings are there on my 13" Late 2010 Air, under Energy Saver. SMC version 1.66f57.

I'm not sure if it's working, though. It does not seem to be downloading emails when sleeping. Does it only work for iCloud email, perhaps?

I have the same model as yours, at SMC 1.66f55. Is that screenshot from a developer build? Still hoping my model is supported, but Software Update lists no firmware updates, and this support article mentions nothing about Late 2010 MBAs.

I'm running 10.8 final (12A269), but I did have developer builds installed previously on this Mac.

I suspect its the SMC version that makes the difference.