Piaggio will be introducing both the MP3 400 and MP3 500 in the U.S. for 2008. Piaggio dealers just met in Scottsdale, Arizona and they were told both scooters are on the way. According to the ScooterScoop, the MP3 500 will be a rebadged Gilera Fuoco 500.
Although many current owners of the Piaggio MP3 report perfectly acceptable power with the 250, some have been waiting for the larger engine versions to appear. It looks like they won't have to wait a lot longer. According to the ScooterScoop article, the MP3 400 may be in dealers as soon as January, while the 500 could be in showrooms around March with a price close to $10,000! A little steep for a scooter but then again, this isn't your average scooter.
Link: The ScooterScoop