We dont know anything really.
1.How those character splay
2.How those stages look now or what games they are mash up with
3.Nothing about the story or how the rival stuff works
4.No idea how those side characters fit into the game.
Its high time they reveal some tbh.
These are the stuff which genreally will lead to more hype.
A trailer on Raiden vs Cole ? It will get more people interested.