Contrary to what seems to be the prevailing opinion, I think we'll see a significant update of the MBP's. From a broad perspective, Leopard was originally targeted for release at WWDC and hardware revisions were likely in place to accompany those revisions in order to take full advantage of Leopard and vice versa. There's really no reason to hold up that hardware to wait on the final release of Leopard - indeed, for all intents and purposes, the wraps are still coming off of Leopard at WWDC.
Furthermore, do you really see Jobs introducing the next gen operating system on a lightly refreshed platform? Envision Jobs walking around telling us about the new Leopard and then going over to a newly redesigned MBP and booting it up from flash memory in a few seconds instead of minutes. I think he shows us Leopard running on a MBP - and that MBP has all the goodies - maybe a redesign, but definitely the led screen, robson, better gpu, etc. I think iMac gets the same treatment. The goal here is to show us that Apple is going to open up a can of Vista/PC whup'ass and that Apple - despite dropping "Computer" from its name - has not forgotten the computing side of its business.
