The interview process was the toughest I've ever been through but it is definitely fair. They want to make sure that you really know your stuff. After the recruiter reached out to me (he was AWESOME!!!) they had me complete an automated skills test on a live system. Hint: Write down all of the tasks that they give you because at the end of the hour the task list will go away but the server will still be up and you can finish your work if you didn't have enough time!
The second interview was a live, technical break/fix session with an actual Rackspace employe. It covered many system administration tasks. Make sure you know Apache, MySQL, file permissions including chmod and umask, how Linux boots up, how to change network settings, how to manage the firewall, etc.
Apparently, I impressed someone because I was asked to conduct several more Skype video-conference interviews from my home and then was asked to join a different team than I initially was accepted to. All told, the process took about a month but I had very special needs concerning my family and they bent over backwards to accommodate us!
I am highly impressed by this organization. I've only been here a few days but I feel like it's already one of the best, if not the best company I've ever worked for, and I've done it all, startup to enterprise.