From the trailer, you can make out 4 stage fatalities.

1.) Column grinder

2.) Knock-opponent-into-lava-stage

3.) Rain stage - Throw the opponent off the platform and into the pit.

4.) Moving platform stage (new pit?) - knock opponent into the spike pit that looks like it's thousands of feet below the arena.

Now if each character has 2 regular fatalities, theres gonna be alot of variation. (plus, there may be more stage fatals.)