There were some changes when Ember 1.0 was released. I’m working on a project where we use older version of Ember (some RC one) and now, because of the deadline we can’t upgrade it. The problem is that there is no info if a method is new, deprecated or obsolete.
I’d propose to use something api.jquery.com uses. I’d make tracking changes very easy. For example we could have a tag 1.1 and we could filter it out.