OS X Lion and MacBook Air refresh July 14 as Apple staff warned of "overnight" prep sessions

Mac OS X Lion is looking increasingly likely to see a July 14 release, with new sources suggesting that Apple is warning retail staff to prepare for "overnights" – late shifts where new signage, displays and hardware are readied for the next day – on July 13. According to 9 to 5 Mac's sources, while OS X Lion won't actually be available on shelves (since Apple has decided to distribute it via the Mac App Store) there will be demo Macs upgraded to the OS, as well as the refreshed MacBook Air.

The Air is expected to see a new batch of Intel Sandy Bridge processors installed, replacing the current Core 2 Duo chips, as well as the addition of a Thunderbolt port like its MacBook Pro siblings. That will allow for high-speed connectivity with external storage and A/V interfaces, which are slowly beginning to appear on the market.

Another, more minor change is the expected introduction of a Facetime HD webcam, replacing the current MBA's lower-resolution camera and allowing for 720p video calls between the updated ultraportable, the latest MacBook Pro and the latest iMac. Most recently, there's been talk of a faster NAND flash technology being used for storage, which would make the MacBook Air even faster.

The July 14 OS X Lion date was first mentioned last week, though rumors of a mid-July Air refresh have been circulating a little longer. Meanwhile, the Mac mini and Mac Pro are tipped to be in line for an update in mid-August.