Once VMware Fusion 2.0 is released, it will be a free downloadable upgrade for all VMware Fusion 1.x customers.  The key features of VMware Fusion 2.0 Beta 1 include:

• True Multiple Display Support
• Experimental DirectX 9.0 3D Acceleration
• Easier to switch to VMware Fusion - integrated Importer and Converter (P2V)
• Virtual Printing
• New Virtual Machine Library
• New Settings Editor
• Shared Folder Improvements
• USB Improvements
• Networking Improvements
• Utility Improvements
• Full Screen Improvements
• Mouse and Keyboard Improvements
• Easier Mac-Native Design

Visit the Team Fusion blog for more information.  You can view details on Bug Fixes and Known Issues in the VMware Fusion 2.0 Beta 1 Release Notes.

What is VMware Fusion?
It is a virtual machine software sold by VMware Inc. that can be installed on Intel-based Macintosh computers to enable them to run x86 and x86-64 operating systems.  These "guest" operating systems such as Windows, Linux, and Solaris can therefore be run at the same time as Apple's operating system, Mac OS X.

For switchers it's the ideal solution
Virtualization software makes the decision to switch easier.  If you're thinking about making the switch but are reluctant to take a full fledged jump to Mac OS X, software such as Fusion will allow you to continue to use an operating system such as Windows, Linux, or Solaris as you become familiar with Mac OS X.  It's the perfect way to ease into the switch.  Furthermore, you'll be able to use software that is only available on a "guest" operating system directly on your Mac.  Thanks to virtualization software, the switch is that much easier.