Apple has started to ask Apple Store employees to prepare for an “overnight” shift on July 13th — a sign that the company is prepping a new release of some sort on the next day, 9to5 Mac said. Apple has already confirmed that Mac OS X Lion 10.7 will land in July, and we’re placing bets that’s what we’ll see on the 14th. However, we’re also expecting refreshed MacBook Air notebooks in the imminent future and, since the new MacBook Air will no doubt run OS X Lion, we wouldn’t be surprised to see it launch at the same time. Other specs for the refresh likely include Intel’s new SandyBridge processors and Thunderbolt I/O in place of the DisplayPort. There have even been rumors of a black anodized aluminum high-end MacBook Air, although we’re not so sure that will ever see the light of day. The good news is we just have six more days until we find out.