I disagree, I think you should wait.
I agree. Take it from someone who bought the iMac G5 two weeks before the Intel iMac came out, because I listened to everyone on this site who said "no way will they update the iMac so soon." There are some big advantages to a Core 2 Duo, most notably the fact that it's a 64 bit processor and Leopard is going to make that more meaningful. Plus the first round of Mac Books has had some problems, a new revision would be nice. And it's always possible that they'll update the video. So wait. The Apple updates in the past year have come rapidly and have been surprisingly meaningful -- just look how much the iMac has gone down in price and up in features in the past year.