It seems that the new Microsoft hypervisor, Hyper-V (formerly codename Viridian), will not come so early: the Release Candidate made available two months ago was the RC0 and not the RC1 as virtualization.info wrongly reported.
The RC1 code has been released today and is available through the Microsoft Download Center and Windows Update services (starting from May 27).
This new build doesn’t bring new features but substantially changes the virtual machines snapshot format, obliging the beta testers to apply or drop them before upgrading from a previous beta or the RC0.
Additionally, this RC is not compatible with the current System Center Virtual Machine Manager 2008 beta.
If Microsoft will take another two months to reach the RTM, the August 2008 release time will be matched.