I should say Supers AND Ultras, but that title was getting a little long. 

I'm not sure what this has to teach us about anything, but it makes me laugh.  I think my favorite is Rose vs Rose Ultra, where the shamwow does zero damage, but earns *both* Roses earn the "first attack" credit, and even knocks them both down. Gen's simultaneous anti-air super also results in a touching mid-air kiss between two diseased old men.

For you game engine nerds, these moves are both being activated on the same frame.  In the case of Ultras, the game assigns the first animation to one character randomly, but the actual execution is totally simultaneous, as you can see from the results.

Thanks Jinrai!