Marc Guggenheim is not only one of the driving creative forces behind CW's hit superhero series Arrow, but he also serves as executive producer on The CW's upcoming spinoff, DC's Legends of Tomorrow, which brings together characters from both Arrow and The Flash. Confirmed cast members include Victor Garber (Dr. Martin Stein), Brandon Routh (Atom); Arthur Darvill (Rip Hunter), Dominic Purcell (Heat Wave), Wentworth Miller (Captain Cold), Ciara Renee (Hawkgirl), Franz Drameh and Caity Lotz. What's interesting is Caity Lotz was one of the first cast members revealed several months ago, but her Arrow character Black Canary was killed off in the Season 3 premiere, leading to her sister Laurel Lance (Katie Cassidy) to take over as the Canary. I recently had the chance to speak with Marc Guggenheim, and I had to ask if he could confirm whether or not Caity Lotz is playing Black Canary, and while he wouldn't reveal her character's identity, we will find out very soon.

"That has been a very closely-guarded secret for a reason. My instinct is you'll get the answer to that question when the trailer... I'm expecting a trailer to be released, and I expect that trailer will answer that question. Unfortunately I can't spoil it here. Too many people would be very angry at me."

The CW will have their upfront presentation in New York on Thursday, May 14, which is most likely when the trailer will debut, although the producer would not say exactly when it will arrive. Who do you think Caity Lotz is playing in DC's Legends of Tomorrow? Be sure to check back tomorrow for the first trailer, and chime in with your theories below.