If I have SQL Server 2008 instances running in virtual machines on a VMware vSphere cluster with vMotion\DRS enabled so that the VM's can (potentially) run on any one of the physical servers in the cluster what precisely are the license requirements?

For example assume that I have 4 physical ESX Hosts with dual physical CPU's and 3 separate single vCPU Virtual Machines running SQL Server 2008 running in that cluster.

How many SQL Standard Processor licenses would I need?
Is it 3 (one per VM) or 12 (one per VM on each physical host) or something else?

How many SQL Enterprise Processor licenses would I need?
Is it 3 (one per VM) or 8 (one for each physical CPU in the cluster) or, again, something else?

The range in the list prices for these options goes from $17k to $200k so getting it right is quite important.

Bonus question: If I choose the Server+CAL licensing model do I need to buy multiple Server instance licenses for each of the ESX hosts (so 12 copies of the SQL Server Standard server license so that there are enough licenses on each host to run all VM's) or again can I just license the VM and what difference would using Enterprise per server licensing make?

Edited to Add Having spent some time reading the SQL 2008 Licensing Guide (63 Pages! Includes Maps!*) I've come across this:

• Under the Server/CAL model, you may run unlimited instances of SQL Server 2008 Enterprise within the server farm, and move those instances freely, as long as those instances are not running on more servers than the number of licenses assigned to the server farm.
• Under the Per Processor model, you effectively count the greatest number of physical processors that may support running instances of SQL Server 2008 Enterprise at any one time across the server farm and assign that number of Processor licenses

And earlier: ..For SQL Server, these rule changes apply to SQL Server 2008 Enterprise only.

By my reading this means that for my 3 VM's I only need 3 SQL 2008 Enterprise Processor Licenses or one copy of Server Enterprise + CALs for the cluster. By implication it means that I have to license all processors if I choose SQL 2008 Standard Processor licensing or that I have to buy a copy of SQL Server 2008 Standard for each ESX host if I choose to use CALs.

*There is a map to demonstrate that a Server Farm cannot extend across an area broader than 3 timezones unless it's in the European Free Trade Area, I wasn't expecting that when I started reading it.