This is a spur of the moment idea and is by no means fully thought out.  Do not criticize that it wont work unless you have some suggestion on how it could work, or ideas to further it's goal.

I was just reading a post about when the new islands were released and how the players had to clear out a lot of roaming spawns before the islands could be inhabited as normal.  This sounds like a very fun group outing and I'm sad that I missed it.

It would be cool if something similar to this happened on a regional level when there is a lack of players in that particular reason for a certain period of time.  Even if an outpost in that region is owned by a corp, if no one is on the ground in that region (docked in an outpost wouldnt count) for a certain period of time a roaming spawn might pop up and roam around said region.  Over time more could spawn up to a maximum.  This would simulate the natives trying to recover their land and/or simply building up a population because no one was there to kill them off.

This would give an unknown element to traveling to areas you don't normally visit.  It may be inhabited or visited frequently by players and you could run into players, or it could be filled with roaming NPC spawns.

These spawns wouldn't have to be anything tougher than whats around it, but could be larger numbers of them, or wander specifically from spawn to spawn so you're more likely to encounter them in larger numbers.

I'm still torn if this should apply to alpha islands, but I think it could still work as the alphas are naturally more populated and less likely to have empty regions for long periods of time.  The amount of time needed could also be made higher on alphas.