If one assumes that the president should be mentioned before the VP, then there will never be a Palin-McCain administration.
There might be a McCain-Palin administration if they are elected.
If this happens, and the old guy croaks, then there will be a McCain-Palin administration, followed by a Palin administration. I forget, does the Congress appoint a new VP or what? Rockefeller was appointed VP for a while after Ford became our first unelected Head of State, both Nixon and Agnew being ousted in disgrace.
It would take a redo of the GOP convention to make a Palin-McCain administration possible.