Back in July CW confirmed that they were developing an Arrow spin-off series based on The Flash. Today we learned that Grant Gustin, of Glee guest-star fame, has got the part.
Gustin will appear on this season of Arrow for a three episode arc (8th, 9th and 20th episodes) as a forensic scientist that attains superpowers—setting the stage for a standalone Flash series. From the official description:
BARRY ALLEN is a Central City assistant police forensic investigator who arrives in Starling to look into a series of unexplained robberies that may have a connection to a tragedy in his past. A comic book fan boy, Barry is obsessed with the Arrow unaware that working with Oliver and Felicity to solve the crime has brought him right into the dangerous world of the vigilante.