Bukkit

I know this is rather old, but I had an idea for this. You could do a for loop such as:

List<Entity> around = creeper.getNearbyEntities(CubeRadius, CubeRadius,
CubeRadius);

    for (Entity en : around) { // keeps looping
        if (en instanceof Zombie || en instanceof Skeleton || en instanceof Spider || en instanceof CaveSpider) {
            Creeper c;
            c.setTarget((LivingEntity) en);

        }
    }

If you can get your mobs to recognise certain schematics by looking for Mob Spawners e.t.c within a 10 block radius, then looking for certain mobs in that radius, this should be an awesome plugin.

Hope it gets to Release!

I could probably help some. If you could figure out some way to recognize some of the basic/most used mob trap designs, I could make the creepers act accordingly and set the target of all the mobs within the design to the closest player. Also, what sort of AI do you need? Please PM me ASAP.