Hyper-V R2 Live Migration Overview & Architecture

There is a new whitepaper that details how live migration in Windows Server 2008 R2 and Microsoft Hyper-V Server R2 works:

http://www.microsoft.com/downloads/details.aspx?FamilyID=fdd083c6-3fc7-470b-8569-7e6a19fb0fdf&DisplayLang=en

http://blogs.msdn.com/virtual_pc_guy/archive/2009/01/29/hyper-v-r2-live-migration-overview-architecture.aspx