Windows Server 8 Hyper-V Network Bandwidth Management
With the new version of Hyper-V which comes with Windows Server 8 Developer Preview you can now manage the Network Bandwidth with a Maximum and a Minimum value.
This allows you to create some SLAs for hosted Virtual Machines.
For example this is a possible scenario:
There are a lot of other networking improvments in Windows Server 8 and Hyper-V 3. You can get some of them in my little Overview about new features in Windows Server 8 Hyper-V: Hyper-V: “Version 3 kills them all”.