Theo posts on his website that the Challenge is filming in New Mexico with some castmembers confirmed

On an interesting note, Theo (Maximum Velocity Tour) posts this on his site:

So another Real World/Road Rules challenge is about to begin filming in New Mexico, and I'm sure it will be a doozy. It's the Battle of the Sexes Two, and supposedly there are a lot of "regulars" on the cast again, such as Miz, Coral, Katie, Veronica, Darrell. However, no one knows who the entire casts are for either team. And I'm certain there will be a few surprises, as always with any Bunim-Murray Production. We'll just have to stay tuned to see what goes down in the dirty Southwest. i'll keep you clowns updated.... cheers... theo

The only new thing about this is that Theo mentions Darrell (Campus Crawl) as a castmember, which is a very good possibility.