"You have invasion of privacy issues other claims that can be brought against the individual releasing the information."
In that letter he released, he is acknowledging that he was born in the hospital. There is no invasion of privacy in this case. I don't see where it would be a violation of HIPPA to confirm it. They are not releasing any private info. on him. By his releasing that letter, he is, in effect, giving them consent to release that specific part of his record which he himself has already released. No details. Just a simple "yes" or "no" - was he born there.
Worldnet is now reporting that some questions have been raised about the letter, and that it's been pulled from the hospital's website: Obama's birth letter: Is this thing for real? See what hospital posted on website for 6 months, then pulled down an hour after this story broke.