http://www.bleedingcool.com/2015/04/24/arrow-season-four-will-have-new-co-showrunner/

The Good:

One of the huge problems of Arrow Season 3 has been the seemingly lack of focus and vision on a main theme or plot line. This could be due to the fact that Andrew Kreisberg has his focus split into several different shows as Bleedingcool reports.

Greg Berlanti is executive producing multiple series including Arrow, The Flash,Supergirl, The Mysteries Of Laura and I may be forgetting one or two. Andrew Kreisberg and Marc Guggenheim are both involved in Arrow, The Flash and the spinoff series (I knew I forgot one) and Kreisberg is part of Supergirl as well. Oh, and there’s the Vixen cartoon too. There are only so many hours in a day so it was obvious that help needed to come from somewhere.

So the fact that Arrow is getting a new showrunner that can just focus on Arrow & Arrow alone is a great thing. Maybe it means we can get a lot more story cohesion. The Walking Dead changed showrunners and that worked wonders for the shows pacing and strength of story. The new showrunner Wendy Mericle is obviously a replacement for Kreisberg who has been doing genius work on The Flash & I suspect will do high quality work on Supergirl.

The Bad:

Although on some shows changing showrunners has been a good thing, there are certainly a lot of shows where the change of showrunners didn't work out well at all. Trueblood & Dexter are perfect examples of where a main showrunner left and the quality of the show left with them. Wendy Mericle maybe highly experienced, but the fact that she is experienced with shows like Desperate Housewives, Eli Stone, and Smallville isn't a good thing. Remember how hokey Smallville was in the later seasons? Drama shows like Desperate Housewives & Eli Stone live on sub plot after sub plot, so is that what we can expect from Arrow? It's too soon to tell right now, but this is going to be a major turning point for Arrow, good or bad.

Wendy on the left during the writers strike?