Aside from the hardware upgrades (PowerMac and PowerBook) there are probably a few extra surprises in store. One I'd put money on is the PhotoPro app as a higher end replacement for iPhoto. There's incentive to add more CoreImage photo editing options, better database controls, more camera support, and possibly a wider selection of Photo Book options. Beyond that Apple certainly has an updated iSight somewhere in the pipe (better resolution, response time, probably smaller too). Apple could also update the iPod Camera Connector (maybe quietly so, but hopefully soon).
Maybe there will be new Cinema Displays with built-in iSight cameras, but I doubt it. Just explaining the details of the improved PowerMacs and PowerBooks and bragging about PhotoPro would take an hour. Any more than that and those "selected media" will have a collective brain overload.