Save the trouble and wait until Snow Leopard ships with the next refresh sometime near WWDC (June 9-12). Don't bet on my prediction, but it's a high chance it's gonna happen. Why impulse now when you can wait just a few more months for a release that has already been confirmed.
Also to everyone saying quad or i7 is coming soon... I cease to believe. Apple will most likely wait until these mobile processors come cheaper for the mainstream notebook lines. We might see it in the 17" MBP Q1 '2010, but not for the other MBPs and definitely not the MB options until later in 2010, at the very least. A BTO would be about right there. Heck, quad could be seen in the iMacs before the notebooks, if anything. Then it's the BTO for the 17", then the MBP 15", and slowly into the MB lines. I wouldn't wait a year for this. Even so, the quad core would be the low-end, and dual core now would probably perform better in some things, besides rendering. Maybe a 10-15% performance boost... if any? Don't bet on my words there either, but it seems that's the rate performance rates go up each refresh anyways.
Good time to buy the MB refresh in the summer with a free printer, and an iPod (if you're going into college like me). That's what I'm doing, and I'm looking forward to it. 🙂