Currently, virtualenv is a separate application, allowing virtualization of Python installations. For Python 3.3, a built-in mechanism is being developed.
Possible GSoC projects:
Creating a test suite for this virtualization mechanism.
Building the standard-library module that will actually create virtual environments, by copying or symlinking the python binary to a given location and placing a default virtualization config file near it.
Important background information to review if proposing to work on this: