I've got an HP ZD7000. This is one of the best laptops for Pro/E because of the large display, numeric keypad, desktop processor and OpenGL graphics card. Mine has a desktop P4 3.2 MHz processor, 1 GB RAM, 80 GB HD, nVidia GeForce FX Go5600 (128 MB) graphics card and 17" display at 1440 x 900 resolution. It's better than my workstation at work except for the display size. Now you can get the 17" display with 1680 x 1050 resolution!
The down side of this machine is size, weight and battery life (large, heavy & short).
You can run Pro/E on smaller, less powerful laptops but I wouldn't want to.