From Cinelinx:
The latest news from DC’s TVU is about a possible spinoff in development that will feature characters from both Arrow and the Flash joining forces in what’s being described as a “superhero team-up show.” The rumor is that the show will have three super heroes who have never been seen on TV before. Which DC characters should appear on the show?
Gravis Ludus' Carl Williams writes, "Right now there are plenty of super hero television shows and movies. This plethora of entertainment should be enough for any fan of the genre. The problem is, a lot of it is spread out amongst competing companies. Whether that be different television networks or movie studios, it stifles the one true thing that can bring fans in- crossover events. That is why I am posing the simple question of is having super heroes from the same universe/brand on different networks is good for business or bad for fans? This article plans to tackle this question based on DC Comics properties."
Variety
DC Comics’ Justice League may be a few years away from fruition on the bigscreen, but the comicbook publisher is steadily building a powerful roster of superhero shows on TV. The CW’s hit “Arrow” has already spawned an equally successful spinoff in “The Flash,” and now executive producers Greg Berlanti, Andrew Kreisberg and Marc Guggenheim are looking to further cement their empire with another super-powered offshoot, this time taking characters from “Arrow” and “The Flash” and combining them in an epic team-up series. The spinoff will be produced by the trio, along with Sarah Schechter.
TV Line: The curious spinoff project featuring characters from both Arrow and The Flash is starting to come into focus, with details on three roles to be cast.
I'd definitely want to see an awesome Nightwing spin-off.