Sure. You'll notice below a heavy duty amount of RAM listed under recommended. About 1GB of this is for the new Windows Vista, but the largest Revit models can be RAM hogs. Personally I find the processor requirements are the bigger must haves. In all, a weak computer can run it fairly easily, its only when you tax it with large models that you really need to worry about the "recommended". So most everyone will be able to demo it and run it quickly, but you need a powerful machine if you plan to use it in 500,000 sf+ production work.
System Requirements:
* Intel® Pentium® 4, 1.4 GHz, or equivalent AMD Athlon® processor
* Microsoft® Windows Vista™ Enterprise, Business, Premium, or Ultimate; Windows® XP Professional, Home Edition, or Tablet PC Edition (SP1 or later); or Windows® 2000 (SP4)
* 1 GB RAM
* 3 GB free disk space
* 1280x1024 monitor and display adapter capable of 24-bit color
* Internet connection for license registration
* MS-Mouse compliant pointing device
* Microsoft® Internet Explorer® 6.0 or later
System Recommendations:
* Intel Core® 2 Duo 2.40 GHz, or equivalent AMD Athlon processor
* Windows XP Professional (SP2 or later)
* 4 GB RAM
* 5 GB free disk space
* Dedicated video card with hardware support for OpenGL® spec 1.3 or later
* Two-button mouse with scroll wheel