This cool new poster for (Green) Arrow and The Flash's fourth and second seasons have been found online. The poster shows Stephen Amell as Green Arrow sporting his new costume and looking super awesome. It also shows Grant Gustin's The Flash sporting his Flash costume with the new white emblem. The Flash returns to TV on October 6th in the season opener named "The Man Who Saved Centeral City", which will finally show veiwers what happened after Barry ran into the wormhole. It should also explain what Firestorm's future in the DCTV Universe is, as all signs are pointing to Ronnie's death. Arrow returns to TV on October 7th in the season opener called "Green Arrow", which will hopefully see Oliver finally become his Green Arrow persona from the comics. Including Starling City becoming Star City. It should also show The Atom with his powers after the explosion at the end of Season 3.
UPDATE
Arrow actor Stephen Amell (Oliver Queen/Green Arrow) recently took to his Facebook to share a picture of the new poster on the WB Building, exclaiming what an honor it is for the poster to be one of the few on the building. Here's the picture he posted below.