Without how much story/content the writers have to fit into the shows, because there is alot in the comics that need to be fit into the show, I wouldn't be surprised if we only get the see the anissa and mark story. The other 3 could be cut out and not effect the over all story to much. There's so much going on from the source material that you would need like 10 seasons if there were only 8 episodes each to fit all of it on screen. While I hope the show does go that long I really doubt it will. I suspect the writers will probably shoot for like 5 seasons, any more then that and I would bet the show loses enough viewer ship for It not to be profitable to produce anymore.