Matt's Inside Line on TVLine has details about Roy's role in Season 3 of Arrow.
Any Arrow scoop that is Roy Harper-related? –Andrew
Showrunner Marc Guggenheim says that Roy is more a member of Team Arrow than ever, and not just because he’s got a mod new Arsenal outfit. “He’s really present and a member of this group, so the trio becomes a quartet,” Guggenheim explains. “And that’s definitely true in Episode 6, [which] is a very Roy-centric episode. It speaks, in some ways, to Episode 212 ['Tremors,' in which Oliver trained his padawan]. I wouldn’t call it a sequel, but they’re thematically related.” All told, the EP says, “What you see in Season 3 is a much more mentor/mentee, master/apprentice relationship. You really see how Oliver is training this kid to be a hero in his own right.”
Arrow returns to The CW on October 8th.