emberjs/ember.js — pull request #5320 by mixonic (2014-08-04 18:10:20+00:00)
Title: [BETA] Deprecate observing container views like arrays

ContainerViews have been observable as arrays, where the items in the array are childViews. This introduces complexity into container views despite the feature likely being a rarely used one.

This commit deprecates the observer behavior in beta. This will inform as to if we can drop observable array container views in 2.0.

/cc @mmun @krisselden @wycats