I've gotten good word from several sources that there are different castmembers who have been conacted about appearing on the next Challenge. Castmembers from Las Vegas, Viewers Revenge, and Denver have all been approached to appear on this next Challenge.
Although there is no news to the location, theme, or castmembers who will actually appear, the next season of the Challenge is confirmed to be in production. This season could begin filming as early as this month and begin airing on MTV as early as this Fall.
The only word about this possible season has been a casting call that was made back in 2006 about a second season of Fresh Meat. Along with the old alumni, a new batch of castmembers may have been casted to appear in this new Challenge, although nothing is confirmed.