The Flash/Arrow spinoff has added a few new names to the cast. They've cast Ciara Renee as Kendra Saunders/Hawkgirl. Looks like there is a rumor that Vixen is getting a tv mini series? Probably going to have ten or so episodes like Agent Carter. Rumored that Stephen Amell will pop up there too? Though don't know how he'll fit that in when he is off shooting TMNT sequel as Casey Jones.
The Arrow/Flash now rumored to be called Legends of Tomorrow after John Wesley Shipp let it slip. Also they seem to have a full central cast now
Brandon Routh - Ray Palmer\ATOM
Caity Lotz - ?? (rumored to White Canary)
Wentworth Miller - Leonard Snart\Captain Cold
Dominic Purcell - Mick Rory\Heatwave
Ciara Renee - Kendra Saunders\Hawkgirl
Arthur Darvill - Rip Hunter
Victor Garber - Matin Stein\Firestorm
Franz Drameh - Jay Jackson
White Canary, Kendra Saunders & Jay Jackson would fill the "three characters new to TV" quota that the producers set up.
As for Vixen...