I am also playing the waiting & wondering game. I have the PB in my signature which is really pokey for iLife 06 and I want to move to iLife 08 and Leopard. I do not want to invest any more money into the PB (2GB RAM, Leopard, ilife08). I have the money in the bank for a new MBP. The thing is that I want my next machine to last me 3-4 years so if the next bump, although minor, is just a couple of weeks away, I can wait for it.
I was hopeful for MW, but honestly that update is not worth time in the keynote. Well not unless they had a full makeover which is more likely coming this summer. Heck if I knew when that was going to happen, I might hold out for that.