Ember 2.0 came out after 1.13, so there's 4 versions between 1.9 and 2.0. 1.13 added a bunch of deprecation warnings to all the features they were going to str

Ember 2.0 came out after 1.13, so there's 4 versions between 1.9 and 2.0. 1.13 added a bunch of deprecation warnings to all the features they were going to strip out, and 2.0 only removed code previously marked as deprecated. So maybe not far ahead of the curve, but they're at least taking steps to reduce their imprint.