Have you heard about that potential spin-off they are making from Arrow/The Flash? The one where they just cast a relative unknown as Hawkgirl? You have? Good, because Arthur Darvill, aka Rory Williams, the Boy Who Waited, husband to Amy Pond and former companion to the Doctor, has been cast as Rip Hunter.
This is awesome for several reasons: 1) we already know time travel exists in the Arrow/Flashverse, so having Rip from the future means more of an exploration of that (perhaps he's from the same time as Dr. Wells?), 2) Arthur Darvill needs to be in more stuff, because he is awesome. Karen Gillen was in Guardians of the Galaxy, so Arthur gets to be in a DC show! Woo!
Now all we need to know is the name of the show. They already said that it won't be The Brave and the Bold. But Rip Hunter was never a member of the Justice League, so I doubt they would name it that, either (as well as the fact that a JL movie is coming out, too). If anything, this show, with it's new and already established characters, seems to be turning out to be like Showcase.