My bet is on Yulai (Concord headquarter) or Jita (because of Jita).
Especially Jita would be interresting. Even if it doesn’t falls into triglavian hands, a siege of that system for some weeks would shake up the economy drastically. And the chaos and panic on Jita undock would be glorious when the first World Ark materializes in the system 
Let’s wait and see, interresting times are ahead in New Eden.