There was an interesting question on EBS training about vitalizing EBS servers and support for such configuration.
The answer is yes. You can run you EBS environment virtualized and it is supported.
Here is also question and answer from Microsoft website…
Does EBS 2008 licensing allow for virtualization? (For example, Windows Server 2008 Standard includes Hyper-V with a license to run one server operating system in Hyper-V.)
For EBS 2008 Standard Edition: You can run one instance of each of the management server software, the security server software, and the messaging server software in a physical or virtual operating system environment (OSE) on up to 3 servers at any one time.
For EBS 2008 Premium Edition: You can run one instance of each of the management server software, the security server software, the messaging server software, and “premium server” software in a physical or virtual OSE on up to 5 servers at any one time. For the premium server software,
You can run an instance of Windows Server 2008 Standard in a physical or virtual OSE; and if you run a virtual OSE, you can run an additional instance of Windows Server 2008 in a physical OSE in order to run hardware virtualization software or provide hardware virtualization services or run software to manage and service operating system environments on the licensed server.
You can run any number of instances of SQL in one physical or virtual machine, and it must be joined to the EBS domain.
You can even find a guide on Microsoft website on how to set up the virtual environment (document is currently not up-to-date and is based on RC0; still it should give you a general idea).