I'm going to need one for grad school before the Fall, but I'm waiting for until WWDC. The last time I got my mac (my G4 400Mhz, which I'm using right now) I was impatient and ordered it the week before the expo....the next week, they released upgrades. So if you don't need it for a bit, I recommend waiting until at least after WWDC. We're too close to not wait.
I'm being optimistic, but I'm going to go out on a limb and hope that with the upcoming release of the Macbook and the price drops in the Core Duo, we might see an upgrade to the MBP with the Merom's at the conference (seeing as last I heard the Merom's were being released around the same time....correct me if I'm wrong here). It would only make sense, as Apple likes to separate its pro line from its consumer line. The cheaper cost of the Core Duo would seem to be better suited in the lower priced consumer line and making room for the higher end chip, that would keep the cost roughly the same for each line. Though, I will admit, we have seen some exceptions to all of this in the last year or so. It's an ideal situation, but, most likely, a pipe dream being so soon from the release of the MBP.
Regardless, I'm going to still get mine in late August and would recommend the same. 😀