There was no reason for Steve to spend his two hour keynote describing new revisions of the Mac boxes to developers.
The WWDC is the Apple Developer Conference (the clue is in the initials). Developers may need to know about new hardware features they are going to have to program for, and *maybe* they'll be interested if Apple can demonstrate that new hardware will make a significant increase in the addressable market. Other than that, they need to know about the new OS features they will get to play with. And that means the emphasis is on software.
indicate that the supply chain for Minis and Pros is drying up. That usually implies an upgrade of the specs is in the wind. They wouldn't need a Steve-note to release them, though. Just a press release will do it.
Demon since forever, HomeOffice MaxDSL since 2006 via Netgear DG834G router
Mac Pro 2.66GHz 8GBytes / MBP 13" - Snow Leopard plus Centos4 & XP Pro in Parallels