Deus Ex 2 is very buggy. On my ATXP 3000+, 1024MB RAM, and 6600GT rig I can barely get 30FPS. The game was directly ported from the XBOX version without any optimization for the PC. I've read about people with better rigs than mine getting terrible performance from the game.
I know there is a patch out there for the game, so you might want to try it out and see if it helps.
Laptops are always a step behind desktops when it comes to performance. As good as some may be, they can't compete with the raw power of a FX-57 running 7800GTX's in SLI. Besides, true gaming laptops defeat the purpose of the laptop, which is that they should be portable and not require you to sit next to a power outlet at all times.