Tonight the Daily Beast has a feature with more information. Palin's Bus Hoax - Page 1 - The Daily Beast Joe McGinnis writes about it.
She has an entourage, including a publicist, and they've covered more than 3000 road miles in her book tour's first week. She flies above in a Gulfstream, at $4000/hour. She says on Facebook, "I'll post our progress from the road." She gives interviews from the bus, to further the illusion that she's traveling on the bus.
Activity log for the plane: here. She has recently been in Richland WA and the plane sat at the Tri-Cities airport for four full days, at $4000/hour. Looks like she needs to go to New York, New Jersey, Arkansas, Dallas, Minneapolis etc. - a very illogical bus route. She slipped up on Twitter and wrote "Just got off flt" and later, "landed in VA." Fake populist.