The Rumor Mill
Unfortunately, The San Francisco Chronicle's Carla Marinucci says there's nothing to the story. Not only does the Terminator still own his trademark Hummers, but his much-touted hydrogen-fueled Hummer remains largely mythical.
On the other hand, it is true that Bill Clinton took delivery of a "Presidential Edition" Mercury Mariner hybrid, just in time for the former Commander-in-Chief's big show in Manhattan.
Who knows? Arnold may make the switch yet.