I want their circumstances to be totally different--like one tribe to living in a cowboy ghost town, and another one on a pirate ship. Once they get to the merge, I want them to find out that meanwhile, two other tribes have been playing in two other themed locales, and that now, the pirates and cowboys have to learn to get along, because suddenly there's ninjas and knights to deal with.
Now
that would be good TV.
Survivor jumped the shark a while ago.