Parallels released http://www.parallels.com/en/products/workstation/mac/ their Windows virtualization solution for the Intel Mac today. The product is called Parallels Workstation 2.1 Beta and a free fully functional copy is available for download now.
Unlike Apple's Boot Camp solution which was released yesterday, Parallels solution allows you to run Windows XP (and other Intel-based operating systems) from within Mac OS X. Rebooting or Dual Booting is not required. This allows users to maintain their daily environment while also being able to use any desired Windows applications. It is only available for the Intel Macs and should provide near-native performance.
Parallels Workstation 2.1 Beta for Mac OS X is NOT simply a "dual-boot" solution; rather, it empowers users the ability to use Windows, Linux and any other operating system at the same time as Mac OS X, enabling users to enjoy the comfort of their Mac OS X desktop while still being able to use critical applications from other OSes.
Parallels appears to be taking advantage of the Intel Virtualization Technology which was included in the Intel Yonah processors that are now shipping in the Intel Macs.
While in free Beta testing at the moment, the final software package for Linux and Windows is priced from the company at $49.99.