Earlier this week Engadget.com revealed that Apple will be previewing the iPhone OS 3.0 at a special upcoming Apple event on March 17th.

Along with the new operating system, Apple also plan to update a revised edition of their iPhone SDK. The iPhone 3.0 event is scheduled to take place 10am PST, and is being described by Apple as an "advance preview of what we're building".

This recent announcement has led many iPhone users to speculate about what new features the iPhone 3.0 will include.

A report from the BoyGeniusReport cites MMS, and USB and Bluetooth tethering as two new features that will definitely be included in iPhone 3.0.

Here's an interesting quote from John Gruber taken from Macworld about his thoughts on the iPhone 3.0 update:

First, a new home screen app (a.k.a. SpringBoard), designed from the ground up for a system where users have a few dozen or more extra apps installed. Managing dozens of apps on the iPhone today is simply a pain in the ass. Second, maybe an answer to the question of where the background notification API is, you know, the one we were told at WWDC to expect a few months ago, but which we haven't heard a word about since. And maybe, pretty please, Mr. Forstall, with sugar on top copy and paste.

Let us know your predictions in the comments!