We received an email from Apple’s iPhone Developer Program, stating that all  submissions to the App store (for both existing applications and new) must be compatible with iPhone 3.0 SDK.  We have done some testing of the 3.0 SDK, now it’s time to take the betas seriously.  I think this could mean Apple could release iPhone OS 3.0 without additional heads-up to the developers, giving Apple the surprise announcement they like so much.

All apps must be compatible with iPhone OS 3.0
Millions of iPhone and iPod touch customers will move to iPhone OS 3.0 this summer. Beginning today, all submissions to the App Store will be reviewed on the latest beta of iPhone OS 3.0. If your app submission is not compatible with iPhone OS 3.0, it will not be approved.