It’s been suggested that unless BHO is actually elected, the issue remains hypothetical and thus nobody has standing. Perhaps the first to actually get standing is Congress when the votes are counted (can’t count someone who can’t be POTUS), or the Chief Justice when the prez-elect is being sworn in (can’t swear in someone who can’t be POTUS). Before then, the Constitution does not address mere candidacy, it just says the President must be a natural-born citizen, so the condition technically doesn’t apply unless someone is actually taking the office. A nit-picking detail, but that’s how the law works.
Roberts: "Barack, before I can swear you in, you must show me your CLOB."
I should think that any voter should be able to ask for candidates to demonstrate their eligibility. But since we elect electors, then it may fall to a member (any member) of the electoral college to request a valid CLOB.
What you say seems correct. If Obama were to be elected (he won’t be), probably the most likely person to have standing would be someone who did not want to comply with an executive order or a statute signed by Obama.