It’s widely believed that Apple will push out a refreshed MacBook Air this month, bringing Sandy Bridge, Thunderbolt and possibly high-speed flash memory to the slim laptop with OS X Lion preinstalled. But the company may have one more surprise in store, with the return of the backlit keyboard.

AppleInsider is reporting that the backlit keyboard missing from last year’s MacBook Air models may soon make a triumphant return, with refreshed 11.6 and 13.3-inch notebooks planned for release this month with OS X Lion already installed. Apple will most certainly upgrade the models with Sandy Bridge processors and Thunderbolt I/O ports, and new high-speed, 400MBps flash memory also seems likely.

“According to people familiar with the matter, backlit keyboards will join the string of hardware enhancements planned for the new 11.6- and 13.3-inch notebooks,” AppleInsider reveals. “The omission late last year of keyboard backlights -- which help illuminate the keys on a keyboard in dim lighting scenarios -- from Apple's current lineup of MacBook Airs was particularly glaring given that all three iterations of the first-generation of MacBook Airs (Early 2008 to Mid-2009) included them as standard features.

“Given Apple's energy saving controls, software expertise, and the nominal cost associated with including keyboard backlights, it was never particularly clear why Apple opted to leave out the feature when it redesigned the MacBook Air line last October,” the report concludes. “One industry watcher even went as far as to call it ‘planned obsolescence’ on Apple's part.”

As it turns out, the move may have simply been a way to initially cut costs for the company, who is prone to iterative releases that slowly add back missing features over time. AppleInsider reported last month that the new MacBook Air models were ready to go, but were being delayed until OS X Lion was ready, in order to have the new operating system preinstalled with shipping models.

According to AppleInsider sources, the new MacBook Air models will debut sometime next week, and given Apple’s long history of releasing major OS X updates on a Friday (at least since Panther 10.3 back in 2003), it now appears that Friday, July 22 is the most likely candidate for both OS X Lion and the new MacBook Air to be released.

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(Image courtesy of AppleInsider and Flickr user zanoii)