need more info
What's missing from your question is what you will be using it for. I just bought a top end MB when a two month old MBP came up on craigslist for $1400. And to be honest, I agonzied over returning my MB and getting it's larger, two month old brother with a 512 mb video card.
Benchmarks show the new MBs to be the equal of the legacy MBP's in processing power, speed, etc. So for my everyday purposes, (surfing, word processing, occasional iPhoto, etc) I probably wouldn't tell much of a difference between the two. The pros have bigger screens, and some argue slightly better. (I honestly could not tell a difference between the new MB and MBP at the Applestore; the pro may have a slightly better viewing angle.)
Do you need Firewire, or the express port? Will you be taking it on the road a lot? Are you a big gamer? Do you have a big honkin LCD monitor at home to hook it up to? Is the pro glossy or matte?
I'm assuming you'll be doing with it the same thing that I am, or else you would have said as such.
Bottom line is, either is an excellent decision, and based upon your needs and preferences. If I didn't just buy the MB, I would have jumped all over the MBP on CL and been happy with it. I'm happy with my MBPM (macbook pro mini). The reason why I didn't return mine is that the restocking charge, plus the extra cash for applecare on the MBP would have raised my TCO up to what I spent on the MB.
Enjoy your new machine!