Somewhat belatedly, Adobe's updated line of software (named Creative Suite v4) makes use of computer GPUs [the capabilities of the graphics chip] to speed up display operations. When CS4 ships in October, it will use the GPU to speed up zooms and pans, 3D rotation, and color correction. A later update adds support for faster effects through GPU-handled pixel blending.
The drawback to relying on GPUs is that the software becomes dependent on specific hardware configurations, as users of SolidWorks and Inventor have come to learn. 'Course, that may not matter if you are already used to Acrobat being slow.