Got the graphic from CNET.  They have some details about the event:

Apple distributed invitations Thursday for a March 17 special event in Cupertino, Calif., to discuss the iPhone 3.0 software and a new software development kit.

Next Tuesday’s event will come a little more than a year after Apple unveiled the original SDK at the iPhone 2.0 software event, setting the stage for over 25,000 iPhone applications to make their way onto the App Store. Speculation about a new iPhone had mostly centered on new hardware features, rather than software upgrades, but it seems Apple has something up its sleeve.

Hoping to see OS-level support for some missing basics:

• Clipboard (cut & paste)
• Background processing (some form of mult-tasking where apps can receive updates even when they aren’t front-most)

I’m wondering if we’ll see any significant hardware enhancements or new models announced.  The iPhone currently drives developers to really focus on a single screen size… would be nice to see more robust handling for multiple sizes/shapes to give more flexibility to hardware in the future.  It’s not that you can’t make resolution-independent applications today – you can.   It’s just not encouraged or optimal.

MegaPhone?