The FIM has issued a revised version of the 2013 MotoGP calendar. The new calendar is only a minor update to the initial calendar issued on September 21st, with only one real change, the switching of the Sachsenring to a week earlier. That move was forced on the FIM, as Formula One had scheduled the Grand Prix of Germany at the Nurburgring for the same date. Holding an F1 race and a MotoGP race in the same country and on the same date was not a viable situation, and so the Sachsenring race was moved.
The other update to the calendar was not a change, but a confirmation. The Grand Prix of the Americas has been confirmed as taking place on April 21st, at the brand new Circuit of the Americas in Austin, Texas. That had been widely expected, but could not be confirmed until contracts were signed. The continuing dispute between the Circuit of the Americas and Kevin Schwantz over the rights to organize the Austin round of MotoGP will not affect the scheduling of the race.