Even AMD dual-core is a bit hyped. There comes a point at which performance becomes a matter of an app loading in 2 seconds, or 3. For me, 3 seconds is not worth the price tag.
I've got an AMD 3200 XP with a GeForce 7800 AGP (yes AGP) and I have no frame rate issues on any games. Granted it's not an AMD 64 FX 50 with a GeForce 7800 GT PCI-E, but it still gets the job done.
When it comes to laptops, just buy what is going to get the job done - or the most bang for the buck.
I'm not saying don't go dual-core, I'm saying don't just get it because of the hype. Hype sells, but hype rarely delivers what it is selling.