I suppose it shouldn't be too surprising that a Green Arrow show is in the works for the CW. The Green Arrow character was one of the more popular additions to Smallville, and throughout the finale seasons of that show, rumors of a Green Arrow spin-off persisted. While this incarnation, titled Arrow, is not in fact a spin-off, its will likely be targeted toward Smallville fans.
I think this is a good character for a series for a few reasons. First off, while not a household name, Green Arrow is one of the best known B-List heroes that would likely not be entrusted with carrying his own movie. He has been heavily featured on DC TV. Aside from his 70 Smallville appearances, he was a mainstay on Batman: The Brave and the Bold and Justice League Unlimited. He currently appears as a supporting character on Young Justice and even landed his own short attached to one of the DC direct to video films in 2010. He also has his own world of supporting characters that could be brought into the series including Black Canary and Speedy. Being powerless, a Green Arrow series would not depend on a big budget.
So where do developing live-action superhero TV series stand?
DC now has in development
Aka Jessica Jones
Cloak and Dagger