John McCain is still running for president. I know this because I see lots of news clips of McCain being introduced by Sarah Palin, and she says that John McCain is running for president, so it must be true.
I assume that what happens is that Palin delivers her rousing intro, the reporters go home, and then McCain delivers his speech. But it's always possible that, as soon as Palin finishes up and the cameras click off, she and McCain may hop back onto the bus and head off to their next gig, without wasting the time that it would take for John McCain to deliver yet another snoozer.
This situation offers one obvious benefit to McCain: The press can no longer criticize what he's saying, because he's not actually saying anything any more. And if the press tries to question what she's saying, it turns out that the press is biased, sexist, and disrespectful, and (according to McCain's campaign manager) is not treating Sarah Palin with the deference that she deserves.
I'm not sure that John McCain can hide behind Sarah Palin until Election Day, but I suspect that he'd like to try. After all, if the current President could refuse to testify in front of the 9-11 Commission unless he could hide behind his VP, there's no reason why John McCain shouldn't be able to continue to use Sarah Palin as a human shield for the next couple of months.