All depends what your doing. For graphic intensive programs and if you NEVER leave the laptop unpluged, the FX-57. if you have the money, should rock.
BUT, I do love my Dell. You cannot beat it, 2 hours battery life (at max), and it powers though everything, adding a 7800 to that is like making a drug that combines everything together. A new Celeron processor is suppose to come out next year, but idk when, and how powerful it will be. Im hoping around 2.5 Ghz(think 4.2Ghz on desktop P4), and hopefully it will be the same pins that way I can ebay it

. The Pentium M is a great little chip though, and can compete with the FX-57 at the now 2.0Ghz that I run, on a desktop with a 6800 Ultra.