Today was the second part of the TCA Press Tour devoted to CW shows. One of the many questions that popped up included Arrow and The Flash universe. CW's Entertainment President Mark Pedowitz announced the questions if Arrow/The Flash will be connected to the other DC shows coming out like FOX's upcoming crime-drama Gotham.
According to Pedowitz Gotham WILL NOT be connected to Arrow or The Flash. He also adds that the Hourman TV script has not been handed in. Its unknown if that is connected to Arrow as well but the Miracle 'Mirikuri' Serum has been a focal point of Season 2.
via KSiteTV
