Sorry, there's nothing TBD about it. It's a birther myth and nothing more. Another country's citizenship laws have no bearing on which American's are or are not natural born citizens. This idea is just another example of birthers trying to distort the law and the constitution to get their way.
Barry stated on his campaign web site, that his birth was governed by a foreign country. The US has no right to tell that foreign country, they have no right to their citizenship laws. Barry, therefore, alleges he was born a dual citizen (assuming HI birth). The question for SCOTUS, and the country remains. Can a dual citizen, at birth, be considered a NBC of the US.