A new version of Apple's iPhone software will be previewed at a special event set to be held on Tuesday, March 17 at the Apple Town Hall.

The invitation for next week's even, which comes just over a year after the company released the original SDK at the iPhone 2.0 software event, was sent out to journalists today.

While few details are known at the moment, we know for sure that the event dedicated to what Apple has been developing lately will focus on iPhone software 3.0, the next generation operating system for the device, despite the recent rumors circulating about a hardware update rather than a software update.

The invitation failed to mention who would be speaking at the event, but with CEO Steve Jobs on medical leave, the runner-ups include marketing chief Phil Schiller and iPhone software guru Scott Forstall, unless Jobs plans on making a surprise appearance.

Apple released its 3G iPhone last summer and the device proved to be an immediate hit with consumers, selling over 6.9 million devices in the September quarter and 4.3 million in the December quarter.

The last major iPhone software update focused on bringing the operating system up to speed with enterprise features. While it is unclear what the new version will focus on, there are plenty of features iPhone users have been clamoring for since its release.