I suppose it all hinges on how well Arrow launches.
To be perfectly honest, i'm expecting Arrow to fail quite spectacularly...
The Aquaman pilot actually showed some real promise, but died a death quickly as well
Aquaman is a joke character though thanks to Super Friends. I'm still not sure it would have lasted more then one season.
Archers seem to be the IT thing right now with Hawkeye, Katniss from Hunger Games, and Pixar's Brave. The CW might as well strike while the iron is hot.