Al is right, it is a little late for this debate. In fact, the original debate took eight years, and we all know the result!
Seriously though, to infer that such founding documents are illegitimate due to the legal status of the composing body is silly. Yes, provincial assemblies, and even the Continental Congress were extra-legal bodies. Any true student of the period knows that. However, such knowledge does not diminish the importance of the arguments they present. The passage of history provides the legitamacy of the Declaration, not the legal status of the composers. At the same time, the end result of Revolution itself contributes to this legitamacy.
I think the example of secession proves my point. Since the secessionist states were defeated in the Civil War, we view their secessionist documents as invalid or illegitamate. Had the South won the Civil War, I dare say we would view their same secessionist documents through a different lens.
Noah