A couple of weeks after the release of Hyper-V 1.0 Release Candidate 0, Microsoft is ready to distribute the drivers needed to optimize the Linux guest OSes.
This drivers allow supported Linux guests (only Novell SUSE Enterprise Linux 10 at today) to access the Hyper-V VMbus, as detailed in this architecture diagram provided by Microsoft in July 2007.
Called Integration Component for Linux, they can be downloaded from the beta site Microsoft Connect.