Many of you may have seen this already, but MacUser posted a roundup of rumors about what's slated for WWDC next week.
These include (in descending likelyhood) Mac OS X Beta, Multiprocessing Power Macs, Apple Handheld, iMac/iBook upgrades, Powerbook upgrades, Apple Network Computer, and Intel-based Macs.
Be aware that all these rumors may apply to either WWDC or MacWorld NY.