So characters with EX specials with super armor can kara cancel the initial frames into their ultra. But it seems that you can also kara cancel the EX to another special!
Around 0:55 Keno does EX rush > EX headbutt. Also note that this only uses up 1 stock on the super meter, just like the EX > ultra kara.
This has the potential to give other specials EX armor that they otherwise wouldn't have. It could also probably give them more range. I need to test this out with Gouken using his EX DP+p cause I believe that move has super armor on it too.