Regardless of the authenticity of the Certificate of Birth, that is NOT the original Birth Certificate which surely does exist and an actual photocopy could easily be released at the request of Obama. Why do you suppose he has refused to do such a simple task and put the question to rest once and for all?
Until he does so, no amount of witnesses and official certificates that are anything other than a true photocopy of the original certificate will put the issue to rest. At this late date, a pretty damned good explanation for not releasing it earlier should also be forthcoming.