Mac Rumors and other mac sites have picked up this comment from an Apple shareholder meeting:
“One additional tidbit from Apple’s shareholder meeting notes was a revealing blurb that Apple still hadn’t completely decided whether or not they will open the iPhone to 3rd party developers.
Jobs did acknowledge that the company is still struggling to decide if third-party developers will be able to create software that will run on the iPhone. It’s a decision Apple “is wrestling with,” according to Jobs.”
This could be good news if they do allow 3rd party apps.