WWDC is Apple's big "professional" event, it's highly unlikely that any of the consumer machines will even get a mention. This year the big focus will be of course on 10.5 but also I think the new Intel PowerMacs and possibly Core 2 Duo MacBook Pros.
iMac, MacBook and Mac mini will see updates either just announced on the website or at a more consumer-focussed exhibitions such as Apple Expo Paris or one of Apple's famous surprise events.