We just finished the final push up of the new Concur.com site. This project was few months in the works with a bunch of extra help. Zaaz Creative did the design and helped out with some of the development.
The project started with a fresh Drupal 6 core, in a fresh SVN repository. I set up SVN post commit hooks so when a developer made a commit our staging server was also auto updated. This was super awesome and made co-development very easy. This also allowed our content teams to work on the sites content as we were pushing up code.