Well, I touched upon this in my Mugello round preview, and I'm starting to think I might just be psychic. According Crash.net, Dorna has announced that the San Marino Grand Prix will be run at Misano in 2007. It's not clear whether one of the existing GPs will be dropped, or whether the season will have 18 races, but my money is on either Shanghai or Qatar being dropped to make way for Misano.
The race is to be run on a "heavily modified" version of the track, in the reverse direction.
~~~ UPDATED ~~~
Since I posted this story, Dorna have announced the official calendar for next year. You can find it here.
