I'm in the 'waiting' category. I don't need a laptop right now, but really do want one. I've got the iMac at home as my main computer, but with two of us in the household, it would be nice to have another option.
I was about to lay down the money for a higher end MacBook yesterday, when I realized for just a few hundred more I could get the low-end MBP (which saves me from the black v. white choice, and provides a bigger screen). However, that few hundred more has convinced me to just wait it out (hopefully no more) than a few weeks to get the most up to date.
If it was a semi-necessity, I would certainly buy now, as it seems the update won't be anything drastic (I'm guessing, just like everyone else on these boards), but if you can hold off and have other computing options, it wouldn't hurt to keep that money in the bank a bit longer.
-anthony