Microsoft has released a very high level document on Windows 8 Client Hyper-V (the actual name for this edition/version of Hyper-V) which you can optionally enable in Windows 8 Pro or Windows 8 Enterprise:
Client Hyper-V is the virtualization technology built into Windows 8. Client Hyper-V is the same virtualization technology previously available only in Windows Server. A similar functionality in Windows 7 is called Windows XP Mode.
Client Hyper-V enables you to run more than one 32-bit or 64-bit x86 operating system at the same time on the same host computer. But instead of working directly with the computer’s hardware, the operating systems run inside a virtual machine (VM).
Hyper-V enables developers and IT professionals to easily maintain multiple test environments and provides a simple mechanism to quickly switch between these environments.
I will not be answering questions on licensing, no matter what mechanism you try to contact me with. Ask your LAR, distributor, or reseller … that’s their job because that’s why you pay them and that’s why they have lawyers
Windows 8 Enterprise gives you up to 4 VOSEs. That means you can install Windows 8 Enterprise up to 4 times in virtual machines that are running on a PC that is licensed for Windows 8 Enterprise. It doesn’t matter what virtualization you use: VirtualBox, VMware Workstation, Client Hyper-V, or whatever. This is not a limit on how many VMs you can create; it is a limit on how many times you can install Windows 8 in virtual machines that are running on the licensed physical PC. You’ll need licensing for any other operating system (Windows Server for example) if you want to install that OS in the VMs that you can run on your machine.
Reminder #1: This applies no matter what virtualisation you use.
Reminder #2: Send your licensing questions to your reseller, not to me.