For a quick overview please watch this video:
http://www.youtube.com/watch?v=n8w8SvvgGV8

Virtual Env Support
New in PTVS 2.0 Alpha

Virtual environments can be now be configured per-project and quickly activated using your project’s “Virtual Environments” node in Solution Explorer. To create a new virtual environment you can right click on the Virtual Environments tree node and
select “Create Virtual Environment…”

You will be prompted for the base interpreter to be used. This is selected from one of the available interpreters configured in Tools->Options->Python Tools->Interpreters and includes all interpreters automatically discovered by PTVS. PTVS
will use this interpreter installation to create the new virtual environment. For this to succeed the interpreter will already need to have had virtualenv installed.
Next you can specify the location where the virtual environment will be created; by default this is your project directory. Finally, give a name to the virtual environment – this is the name of the folder that will be created on disk.

Once you click OK, PTVS will create the new virtual environment and add it to Solution Explorer. If you have an existing virtual environment you’d like to use with your project you can choose “Add Virtual Environment…” instead and provide the directory
where you’ve already created the virtual environment.
PTVS also supports track the packages which are installed into your virtual env and let you install new packages without leaving the IDE. To install a package right click on the virtual environment and select “Install Python Package…”

You will be prompted for the package name to be installed:

Type the name of the package you’d like to install and click OK. PTVS will use PIP to install the package and the output of the installation will be printed into the output window. After installing a package, you’ll see that it is listed below
the virtual environment in Solution Explorer:

To uninstall a package, right click on it and select “Uninstall Python Package”. The package will be removed from the virtual environment and the result of uninstalling the package will be shown in the output window.
Finally, once you’ve configured your virtual environments, you can quickly switch between different Python interpreter configurations. To choose your current virtual environment, right click on it and choose “Activate Virtual Environment”.

Activating the virtual environment will cause PTVS to use the interpreter and libraries that are in the virtual environment when running or debugging. To switch back to the default libraries, you can deactivate a virtual environment. This will
leave your project configured against the base interpreter of the virtual environment. The currently active virtual environment will be highlighted in Solution Explorer with a bolded name and a small overlay icon:

In PTVS 2.0 Alpha there are still a few known issues with virtual environment support, as well as some features yet to be implemented. We’d appreciate any feedback about what else you’d like to see supported with virtual environment, so please vote
for the issues below or let us know if we missed anything.
Intellisense is currently not enabled against the packages installed into a virtual environment
Python 3.3’s “venv” is currently not supported
Enable/disable virtual env are not dynamically being enabled/disabled based upon the active virtual environment
Virtual env’s should support creating REPL’s
Virtual env should support searching PyPi
virtual env should automatically open output window