The AMD vs Intel debate for CPUs has been ongoing for a couple of decades now... Plain truth... a dual core AMD will outrun a dual core Intel (with hyperthreading enabled) at the same clock speeds... not by a whole lot, but it will be faster.
That would have been true a while ago, until the introduction of Core 2 series. Core 2 was based on Pentium-M, an extremely efficient architecture, with instructions per clock almost twice as high as P4, which was a fair bit slower than AMD clock for clock.

For desktops, some people choose AMD CPUs because they are usually cheaper for the same performance, and some lower end CPUs have unlocked multipliers. For laptops though, you'll most definitely want an Intel CPU. Intel platform (both CPU and northbridge) power management is much much better. That means less heat, and longer battery life. I have a laptop with 2.5GHz Core i3 CPU that can run for about 8 hours on a charge. Nothing from AMD comes close. If you look at current laptop line-ups, only lower end machines use AMD. No (very few) high end laptops use AMD CPU. I would definitely pay a little bit extra to get Intel.