I have some ideas:
1) a brand new task choice to the race like "Oneway" where one team chooses another team to do an extra additional task that will slow them down. This is not the same as the U-Turn which involves the Detour, its more like an additional task.
2) have them visit places like Kalgoorlie in Western Australia, Easter Island, Boniare, Curacao, Sint-Maarten, Bermuda, and have the starting line like in Alaska or Hawaii.
3) like to see some new teamings: Uncle-Aunt/Niece-Nephew, Godparent/Godchild "in the US Version," multi-racial team "African-American/White" (not married/dating)
4) like to see some teams with new titles: Fishermen, Rock Musicians, Military Buddies, etc..