I must admit, the NW's are your best bet if you're going to overclock, no doubt about it. In fact, I'm looking into getting a full fledged 1.6 or 1.8A Intel rig. I just started a thread about it in fact.
Right now, if you wanna do some extreme overclocking, go with a Northwood. If you don't overclock, then go with AMD.
Of course, the situations could be easily reversed in the next couple months, and so on and so on and so on.....