Aside from perhaps GSP, I do not foresee there being any other champs but Americans. Let's take a look at the divisions as of now
Heavyweight: Cain Velasquez
Light Heavyweight: Jon Jones
Middleweight: Anderson Silva
Welterweight: Georges St-Pierre
Lightweight: Ben Henderson
Featherweight: Jose Aldo
Bantamweight: Renan Barao (ic)
Flyweight: Demetrius Johnson
The color codes are as followed:
Green: No danger of losing
Blue: Slight risk of losing
Orange: Very possible to lose
Red: Strong chance to lose
As you can see, the only people I feel are locks for their division are Jon Jones and George St-Pierre. Also, while Lightweight and Flyweight are Blue, you must realize that the only threats to the belt are Americans.
Jose Aldo and Anderson Silva, while outstanding fighters, are at a bigger risk than any other champ. Aldo is dealing with former LW champion and p4p ranked Frankie Edgar, who will be fighting at a weight class similar to his actual size. Anderson is dealing with the inevitable effects of old age, as well as his potentially biggest test to date in Chris Weidman.
Renan Barao, while considered the Interim Champion now, has two very big tests that I personally feel he cannot pass: Mayday and Cruz. The former can KO him and the latter will defeat him 50-45, 49-46 at worst IMO. He's a placeholder currently.
So basically, I see the next year looking like this:
Heavyweight: Cain Velasquez (I feel he beats Overeem via pressure)
Light Heavyweight: Jon Jones
Middleweight: Chris Weidman
Welterweight: Georges St-Pierre
Lightweight: Ben Henderson / Gray Maynard / Michael Chandler (all have potential to be number 1 now)
Featherweight: Frankie Edgar
Bantamweight: Dominick Cruz (king returns)
Flyweight: John Dodson (hopefully)