Windows Vista introduces a new Mobile Device Center, which replaces Activesync for Windows CE and Windows Mobile devices.

Mobile Device Center is not built in, at least not with the initial release of Windows Vista.  You must download and install it from the link above.

Using the Mobile Device Center is very similar to using ActiveSync.  Primarily the major features still exists but have been renamed.

When you connect the device, you will see the Setup screen, shown below:

If you select 'Connect without setting up your device', you will establish a connection similar to a Guest connection under ActiveSync.

Selecting 'Set up your device' will establish a partnership.