Why so?
Remember, this case is about "Terri's Law", not about Terry directly. That distinction may be hard for some people to grasp, but it hinges on that. The US Supreme Court is simply not going to tell the Florida Supreme Court that a law it ruled unconstitutional under the Florida constitution is okay after all.
Or, if it does, I will be amazed. I can't recall a previous case where they've ever done such a thing absent some significant federal issue being raised in the appeal. Governor Bush's attorney's have tried to assert that some federal issues are involved in order to get US Supreme Court jurisdiction and interest, but they're really weak longshots.