Not happening unless the U.S. Constitution gets amended that changes the "Natural Born Citizenship" requirement for eligibility to be President or Vice-President to something like "Citizen, either Natural Born or Nationalized".
Amending the U.S. Constitution can be done by either getting 2/3rds of each house of Congress to vote to approve an amendment, then they must send it to the states, where 3/4 of the state legislatures must vote to ratify the proposed amendment. The second way requires a Constitutional Convention, where 2/3 of the states must petition Congress to convene a Constitutional Convention and then 3/4 of the states must ratify any amendment to comes out of a Convention.
My own two cents on this, no way will the Constitution get amended to formally allow Nationalized Citizens to become citizens in Arnold's lifetime. Who knows what will happen in 30 or more years, especially if the illegals ever get amnestied and become citizens.