A scan of the Supreme Court docket sheets shows that two more cert stage amicus curiae briefs have been filed--one by the Western Center for Journalism is HHS v. Florida (No. 11-398) and one by Lawrence J. Dickson, PhD., in Florida v. HHS (No. 11-400). I have been unable to locate copies of either brief, however. If someone out there happens to have one--or any other amicus briefs that I have missed--please feel free to send them my way, and I will be happy to post them.
UPDATE: I have found the Western Center for Journalism's brief on Westlaw (though not in a PDF form). And the second half of its argument is a "birther" claim--that the ACA is invalid because federal legislation must be signed by the sitting President (absent a veto override), and "Mr. Obama has not yet verified whether he meets all of the requirements for minimum eligibility, namely whether he is a natural born citizen." Needless to say, this claim was not raised by the challengers below and is not within the questions presented in the petitions.