Earlier today, Apple released version 2.2 of Boot Camp drivers for Windows. Installation requires Boot Camp 2.1 to have been previously installed as well as Service Pack 2 for Windows Vista.
Boot Camp is included with Leopard and Snow Leopard and lets you install Windows on an Intel-based Mac. Shops or individuals who want to go Mac despite an unavoidable Windows-only application should consider Boot Camp along with virtualization options like VMWare and Parallels. For full information on installing Boot Camp as well as upgrade instructions, manuals, troubleshooting tips and more, look here.
Please note that Boot Camp Drivers Update 2.2 is for Mac OS X 10.5 Leopard only.