I've just installed Windows 7 and started to have a look at the new Windows Virtual PC. There are a couple of nice new features.
First of all, you can now save notes as part of the Virtual PC configuration file, so you can record any relevant information about the virtual machine. In addition to that you can also save the logon credentials for the virtual machine in the configuration file, so you don't have to worry about remembering passwords for all various virtual machines you might have.
Second, it's now much easier to access the contents of virtual hard drives without firing up a virtual machine. If you run the Windows disk management console (diskmgmt.msc), you'll see that there are two new options on the Actions menu that enable you to mount a virtual hard disk in Windows, and to create a brand new virtual hard disk. Once you’ve created your virtual hard disk, you can initialise it and format it just like any other disk on the system.