WB and DC's "Arrow" is the current biggest superhero thing on TV (much more popular than Agents of SHIELD), so much that it even spun off a show about the Flash, and now probably the Atom. it is basically green Arrows story, mixed a bit with Batman lore to keep it a bit darker... and most likely since an actual Batman show would have been rejected due to the Nolan movies at the time. None of the current shows have anything to do with Smallville.
"the Atom" / Ray Palmer is the DC "super shrinking" guy. Your thinking "Ant man" / Hank Pym, who is marvel's super shrinking guy and the guy who created Ultron. Though the Atom can shrink far more than Ant man.
And no, the TV Arrow/Flash/Atom (and upcoming Supergirl) will NOT be apart of the new DC movie franchise... Much to a lot of fans disappointment. They are their own thing, but since WB owns all of DC, they can choose to have 2 different universes if they so desire.