The Task Manager in Windows Vista (RC2) has improved somewhat since Windows XP. There are some really nice new features that makes the Task Manager more useful.
First of all the Processes tab has been split into two: Processes and Services. This will makes it more easier to find the processes in the lists and the lists has also been improved with descriptions of the processes. On the Services tab you will also find a shortcut to the Services Management Console.
The Performance tab has gotten a facelift with a shortcut to the Resource Monitor which will give you much more information on the usage of the resources of your machine and is far more useful for measuring performance (which Task Manager never was intended to be used for).