I think that iWork and iLife may have some sort of Leopard Special Goodness and they can't show them off without showing off leopard first. Bunches of Indie Mac developers are doing leopard only next versions (Delicious Monster, Textmate, etc...) Some for core animation, some for garbage collection in Obj C 2.0. Apple all but started this trend by abandoning panther with Safari 2.0 (and I'm sure there are other examples.)
Is anyone else upset/confused why Apple didn't show off iLife '07 and iWork '07. I find it annoying that I just got a new Mac and starting using iWork, thinking the new version would be out when my trial ended.
It's also weird that every Apple prediction site pretty much guaranteed new versions. Macworld has always been the place to show off the new software suites. What gives Apple!?!