The updated version of this is over here: http://www.slideshare.net/nadavoid/upgrades-and-migrations-bad-camp. I updated it for BAD Camp 2013.
You have an aging Drupal 6 or even a Drupal 5 site. You know it's time to move up to Drupal 7. Now, how? There are two main ways to get there. You can perform a traditional upgrade, or you can migrate the data from the old site to a brand new site. In this session I will show how you can use these methods and discuss their benefits and drawbacks, including a thought process to go through when evaluating these options, drawing from some recent projects.