Symfony 2.0.12 has just been released.
If you are starting a new project, you can get the Symfony Standard Edition distribution on the download page.
Then, run the vendors script (it also clears your cache):
$ ./bin/vendors install
Remember that the Symfony2 Components are also available as standalone libraries. You can get them via their dedicated read-only repositories on Github (https://github.com/symfony/Finder for instance), install them via PEAR (pear install symfony2/Finder), or even install them via Composer.