Unable to query slotted nodes created by dom-repeat

[TomK]

When slotting a dom-repeat, i am unable to query the generated items.
Possible regression of #2276

Live Demo

http://codepen.io/oridan/pen/JbWrxv?editors=1000

Expected Results

console log should show something like:
[x-items] [slot]

Actual Results

console log shows
[] [slot]

Browsers Affected

• Chrome

Versions

• Polymer: 2.0-preview
• webcomponents: v1

[TomK]

Closing after discussion in slack. Thanks to @arthurevans suggestion of stamping elements into light dom as follows:

_attachDom: function (dom)
            {
              this.appendChild(dom);
            },