23-inch iMac on September 12th? [Update]
MacOSXRumors now claims that Apple will be revamping the iMac line with the new Core 2 Duo processor at this event, with the additional introduction of a 23" iMac.
Larger iMac form-factor rumors were amongst the reject rumors for pre-WWDC rumors. MacOSXRumors, however, cites "reliable sources" for this report and did have some accurate predictions for Leopard (virtual desktops, tabbed iChat).
Update: Appleinsider also believes that the iMac will see Merom updates in mid-September along with a 23" iMac model.