Following my journey with Windows 7. I am glad to report, that I have installed and tested the XP Mode successfully. For those not knowing what this is, Microsoft in their infinite wisdom gave us the option to run Windows XP as a virtual session on Vista for free. You need two files: the Virtual PC, and the Windows XP mode file. You also need hardware that can support this. You need the VT technology from Intel, or the Virtual Technology from AMD.
Once you verify that you can run it, you download and install it from here. The cool thing that you can do is run applications, that you install in the XP as applications that run in the XP mode apart from being in the Virtual Machine window. Interesting, VMWARE Workstation has been doing it for quite a while with their Unity feature, but having as a free option really is a good thing from Microsoft.
So far Windows 7 is a hit. I think that Microsoft learned a little lesson, and finally released Vista in a form that it should have been in the first place. So far so good. I have not heard of any big negatives just yet.