And yet, no new iPhone will be present ... I predict a lot of attending hearts will be broken!
If your paying $1600 just to see the new iPhone unveiled you are going for the wrong reason.
The fact that there may not be a new iPhone announcement must mean that their software announcements will be even bigger. Which is good for developers. It is a developer convention after all...
The new iPhone will come eventually. It was nice having it launch in the summer to help boost the summer month slump, as the highest sales are typically in winter then fade out slowly through the year, with bumps happening at new product launches. So moving the iPhone launch to later will make its effect quite different I think.