In order to support a beta-to-beta upgrade path for Drupal 8 users sooner, the core committers have posted a proposal that recommends re-activating the http://drupal.org/project/head2head project in contrib and building the beta-to-beta upgrade path there in the short-term. This allows early adopters to have access to an upgrade path much earlier than core would be able to provide, and also gives us a "safe space" to test beta-to-beta upgrades prior to supporting them formally in core, without slowing down our current velocity on critical issue fixing.

Please share your thoughts, especially if you're one of the adventurous early adopters who are actively building on Drupal 8 already!