May 31, 2011 11:48 GMT  ·  By

There’s a chance Apple will fill up some time at the WWDC 2011 keynote with new Macintosh upgrades, including new versions of the super slim MacBook Air as well as new Mac minis equipped with the Sandy Bridge platform from Intel, and Thunderbolt I/O.

This week kicked off with reports saying that Apple’s MacBook Air computers were due for another hardware upgrade, following the October 2010 refresh that saw Apple’s ultra portable laptop gain a new form factor, new screen configurations, solid state storage, slightly bumped CPUs, and more.

The notebooks, however, are now falling short of a couple of enhancements that Apple introduced soon thereafter inside newer MacBook Pro and iMac models - Intel’s newer CPUs code named Sandy Bridge, and the Thunderbolt interface for connecting peripheral devices to a computer via an expansion bus.

Sources are saying the Air is on track to receive these enhancements with an estimated shipping date of June-July for the updated models.

This would still leave two Macintosh models that haven’t seen these implementations, namely the small Mac mini desktop computers, and Mac Pro workstations.

Based on visibly increased number of Mac mini refurbs selling via Apple’s Special Deals section lately, we’re inclined to believe the same upgrades are to be applied to the mini, sooner rather than later.

In fact, going by when the latest Mac minis were introduced (June 2010), they should be getting a hardware upgrade first.

However, with Apple expected to feature no iPhone announcement at this year’s Worldwide Developers Conference, most bets are on the OS X Lion preview, a glimpse at iOS 5, as well as these potential under-the-hood speed bumps we’ve been ranting about for the past eight paragraphs.

At the very least, we can expect Apple to up the ante on the hot-selling MacBook Airs, with the Mac minis and Mac Pros sure to follow soon.