__nextSuper showing up in property ennumeration

Hi, I’m not sure what’s going here but I’ve just begun to see the __nextSuper property on ember objects show up when enumerating, like in a for...in loop. I’m not sure why its showing up, the __nextSuper property is marked enumerable: false in its property descriptor. I’m wondering if this is some type of bug or regression in Ember.js? I What could cause a property to show up while enumerating, when it is set enumerable:false in its property descriptor?

Here is a jsbin that illustrates the problem: http://emberjs.jsbin.com/tavuti/1/edit?js,console

Just confirmed that this is not happening in 1.6: http://emberjs.jsbin.com/tavuti/2/watch?html,js,console

With a followup ticket at GitHub for interested readers.

Any update on a fix? I downloaded 1.8.0-BETA.4 and this problem still exists.