As the Subject says, here's a link to the exam objectives aka "Skills Being Measured for the 71-620 Windows Vista exam:
www.microsoft.com/learning/exams/71-620.mspx
Note the title for the exam: "TS: Microsoft Windows Vista, Configuring"
The exam objectives include a lot of "Configure ....", and some Troubleshooting and some Install/Upgrade... I'm not sure, but I think this is because of the MCDST Vista.
For those who aren't familiar with MS exam codes, the '71' indicates the exam is a beta version. So the exam code for the Windows Vista exam will be 70-620.