I think the best way to shake things up especially in Null-Sec is to change the Resource System.
- Mineral Resources Availability.
- Combat Sites Availability (anomalies).
- Cosmic Signatures Availability
- Rare Loot Drops.
CCP should change the Availability of Resources in EVE especially in Null-Sec.
Or better yet, CCP could create a really Dynamic Resource System. Creating greater incentive for Mega-Corps to clash in search of new resources.
In the context of this new Dynamic Resource System, the resources in the Delve Region should already be very depleted.
This would force the Mega-Corps to move to a more resourceful region, and so on so forth. This constant movement should help combat Null-Sec Stagnation and Consolidation.