In addition to some cast changes, Arrow is undergoing a big change on the broadcast front too: moving from Wednesdays to Thursdays and, more pertinently, from 8pm to 9pm.
The later slot is crucial, because it opens the door to new storytelling and filming possibilities. Arrow is already a dark, violent show that deals with mature themes, but it can do even more with a later timeslot. We saw that happen with Agents of S.H.I.E.L.D. Season 4, and Arrow should be able to really utilise the extra leeway.
The show was great when it first started out, but it's been usurped in the dark, brutal superhero stakes by the likes of Daredevil on Netflix. It might not get to those heights, but a later timeslot should help it redress the balance somewhat.
What do you think will happen in Season 6? Share your thoughts down in the comments.