Change effective on 04 November 2014
Cedar-14 is now generally available and is the default stack for apps created on Heroku. See the migration guide for details on how to migrate apps to Cedar-14.
As of today, the classic Cedar stack is deprecated. Builds on apps not migrated to Cedar-14 by November 4th 2015 will be disabled (you can create builds for an app again after upgrading to Cedar-14).
NOTE: A previous version of this changelog entry stated that apps not upgraded by November 4th would stop running. This is not the case. You will not be able to push to a Cedar-10 app without upgrading to Cedar-14 after this date.