Update: 26th June 2008. Hyper-V RTM is now available. RC0 is pre-release software.
The Vista SP1 Management Tools for Hyper-V RC0 are now available for download. These include Hyper-V Manager, the MMC management console, and Virtual Machine Connection, which provides a remote console for virtual machines. After installation, Hyper-V Manager is available under Administrative Tools on the control panel. There is no direct shortcut created for Virtual Machine Connection.
In Windows Vista, Administrative Tools are not, by default available on the Start menu. However, if you right-click the Start button, choose properties and then click customize next to the Start menu option, down the bottom of the list is the option to "Display on the All Programs menu and the Start menu".
Download the appropiate version according to the architecture of your Vista SP1 machine:
Windows Vista SP1 information and download links can be found here.