Q: What are the differences between the Self-Service Portal that ships with System Center Virtual Machine Manager (VMM) 2008 R2 and VMM Self-Service Portal 2.0, which is available as a separate download?

A: The Self-Service Portal that's supplied with VMM 2008 R2 is a simple IIS web application that works with the SCVMM server and does not require its own SQL database. The 2008 R2 Self-Service Portal provides a basic quota scheme where points are assigned to each virtual machine (VM) template and users are assigned a number of quota points for VM creation. You administer the self-service portal through the VMM Administrator Console.

The VMM Self-Service Portal 2.0 is made up of several of components, including a web application, a server component, and its own SQL Server database. It supports more powerful allocation of VMs based on CPU and memory, instead of basic quota points. It uses web-based administration and granular policies for VM allocation and access.

For a detailed comparison, see this Microsoft page.