Given that the W3C charter requires actual implementations in order for a standard to move forward, I'd have to say that no - entities other than those who might produce a significant implementation probably don't matter in this case.
The W3C Process considers all implementations equivalent: if you were to implement DOM 4.1 in Python, that would be as significant as a browser implementing it. That said, each group has to define what they'll consider "sufficient implementation experience" for each spec when they publish a Candidate Recommendation: the DOM 4.1 spec does not do this, and this forms part of Apple, Google and Mozilla's objections to the spec advancing to CR.
The DOM 4 implementation report, http://w3c.github.io/test-results/dom/details.html, is based on the tests in web-platform-tests: however, the web-platform-tests policy is that we test what browsers implement, and hence the DOM tests there are based on the WHATWG spec: there's no evidence provided that anyone has implemented what the W3C spec says in any case where it differs.
Given that the W3C charter requires actual implementations in order for a standard to move forward, I'd have to say that no - entities other than those who might produce a significant implementation probably don't matter in this case.