well in the comics Superman and Flash raced each other plenty of times so it could be a nod to it xd
They did that in Smallville as well. It was close then Bart really tried and blew Clark away.
I think this means they have faith that Supergirl will at least get a 2nd season.
I'm very interested in seeing how this will connect with the Arrow/Flash verse because this means Superman is around in there verse unless the pull Supergirl is from Earth 2?
And if they do do that what is interesting is the "Crisis on infinite Earths" I'd say both Barry and Kara where the 2 biggest casualties of that arc.
At some point Superman has to appear on Supergirl and what sucks is I think without question Brandon Roth would have played a TV Superman but he's taken.
So my hope is they get Tom Welling to do it but I doubt that will happen but maybe if they through enough money at him he'd do it.
Say what you will about him but I watched him play Clark for half my life so for me he is my Superman so it would be awesome to see him reprise that role.