In some respects, these arcs will open up pirate faction mission running for many players, given that completion of an arc will impart a 30% standings gain towards that faction. Players have long wanted a way to repair their negative standings towards New Eden's pirate factions and this seems to be the first step towards that. Still, that standings gain won't benefit players who are particularly loathed by a given pirate faction unless the arcs can be repeated some months down the line as with standard Epic Mission Arcs.
If you want to learn more about the new content, give "Epic Pirates Use Speed Boats" a read. It will also help you figure out which mission agents and locations will be an ideal starting point if you're thinking of trying these out in Dominion.
Just for the sake of curiosity, empire mission runners -- will these pirate mission arcs be enough to entice you out into 0.0 for a different take on PvE? And for those readers who already have good standings with the Angel Cartel or Guristas -- does it surprise you that pirate Epic Mission Arcs are being made so accessible to everyone else?