Rev A
I have been struggling with this buy or wait issue myself. I played with Photoshop CS2 at Macworld, and true it didn't blow me away, but it still runs hecks of faster than PS 7 does on my Powerbook (867mhz tibook). I can only imagine the performance once the universal Binary versions are available.
Then again it is a Rev A. and there have been some bad ones. The B+W G3 Rev A is a fine computer - if you like to replace logic boards, for example... G3 Kanga? you get the point. This is a different Rev A for Apple however, with the Power PC chip Apple had to engineer the CPU Bus to the logic board, which is were many of the Rev A glitches were... This time the bus is being supplied by the chip manufacturer and is a pretty amazing bus at that. PCI express busses have been proven, and shouldn't have many issues, if any.
Also the Macbook Pro is sooo pretty. I love that it is back to the svelte form factor of my Ti book, but with better hinges. Frankly I think Rev B, might offer some nifty features and could be worth the wait, especially if you want a 17" model, but really I don't think you will have regret either way.