vm2dmp is a newly released tool to create a complete memory dump of a Hyper-V virtual machine:
http://code.msdn.microsoft.com/vm2dmp

Along with the Debugging Tools for Windows, it can be used to view the valid memory pages of a virtual machine’s snapshot state or saved state.

Very useful if you have a VM which is hung and it is not started in debug mode or configured for a manual dump, or is so frozen that even the Integration Services components do not allow a manual dump to be produced inside the guest.

Also, as it doesn’t actually bugcheck the guest, it can be used in a similar way to ADPlus’ “hang mode”.