Hyper-V went RTM officially this morning.  Some fixes I've noticed already:

• Closing the Virtual Machine Connection window no longer yields a program crashed exception.
• VMs start, stop and save much more quickly than in RC1
• Machine Save State files are able to be used after the RTM upgrade (not so going from RC0 to RC1)

Press Release:
http://www.microsoft.com/presspass/features/2008/jun08/06-26hyperv.mspx

Download full RTM bits:
http://www.microsoft.com/downloads/details.aspx?FamilyId=F3AB3D4B-63C8-4424-A738-BADED34D24ED&displaylang=en

Vista SP1 x64 Management Console:
http://www.microsoft.com/downloads/details.aspx?FamilyId=88208468-0AD6-47DE-8580-085CBA42C0C2&displaylang=en
Vista SP1 x86 Management Console:
http://www.microsoft.com/downloads/details.aspx?FamilyId=BF909242-2125-4D06-A968-C8A3D75FF2AA&displaylang=en
Server 2008 x86 Management Console:
http://www.microsoft.com/downloads/details.aspx?FamilyId=6F69D661-5B91-4E5E-A6C0-210E629E1C42&displaylang=en