Following on the vSphere 5 License adjustment, VMware recently released the vSphere 5 License Advisor. This is a tool that you can use to run against your vSphere 4.1, vSphere 4.0, or Virtual Infrastructure 3.5 deployments to understand how the vSphere 5 vRAM licensing entitlement will affect your installation.
Note: I’ve heard some comments that the tool may have some reporting issues in the GUI with deployments in excess of 1000 VMs, but that the exported report is correct. I would appreciate anyone who can validate these reports…