I followed parts of this tutorial to setup opencv in virtualenv.
The cumbersome part is that everytime i create a virtual env, i need
to copy opencv to the lib folder. But hey, it works!
In a nutshell..
$ brew install python $ pip install numpy $ brew install opencv
$ cp /usr/local/lib/python2.7/site-packages/cv*
/lib/python2.7/site-packages is the path
where you have created your virtual env.
Hope this helps.