A: Windows Server 2008 R2 SP1 introduced dynamic memory and RemoteFX, which require changes to the management interface and logic for virtual machine (VM) placement and reserve calculations. SP1 for VMM 2008 R2 will add full support for the Windows 2008 R2 SP1 Hyper-V features, including configuration of settings and checks for the placement (i.e., does the target node support RemoteFX? If the VM is running, does the target have sufficient memory for its current usage if using dynamic memory? If it's RemoteFX–enabled, is there sufficient graphical memory on the target?)
Note that to set the priority of the memory allocation when using dynamic memory, you should scroll to the Advanced VM properties area. The memory priority is set in the same location as the CPU priority.
One of the nice features of VMM 2008 R2 SP1 with RemoteFX is that it shows details of the GPUs along with available graphical memory on the host that's available for allocation.