Today, I spent the day in the pre-conference Drupal core sprint. There were at least 80 - 100 people who stopped by for at least part of the day to work on open issues for Drupal 8.
I worked on a couple issues related to converting the menu route to the new style of controller as part of the WSCCI initiative. It was a good chance to learn the new menu routing system, which is object-oriented and a big change from the Drupal 7. It was a decent slog to figure it out, but I the WSCCI Conversion Guide was a big help. A list of the open menu routing conversions can found here: http://drupal.org/node/1971384