The significance is this: A court martial will open the trial to discovery of evidence. The judge will have to order the actual birth certificate (the issue at question) to be entered into evidence. Obama has spent lots of money preventing the documents from being discovered up to this point; I don't know what strings he may pull to stop them now.
Allowing the Birth Certificate into evidence hopefully will finally resolve the question of O's birthplace.
This is why the Lt. Col's case is so important. All the other military folks have simply had their orders redacted- thus prohibiting the discovery of the birth certificate.
For all the "birthers" out there, this is a good thing. It will end the debate. For the non-birthers, this is a good thing; it will end the debate.
My opinion is that it will NOT go to trial; the big O (no not Oprah) will simply demand that the Pentagon change his orders and not hold a court martial.