In order for exploration to be enjoyable the world needs to be fun to explore obviously. In my opinion the best exploration comes from the players desire to simply learn more about the game world. Right now exploration is basically going from point A to B while attempting to complete objectives, and while the world is vast and beautiful I never find myself just randomly exploring.
One thing that would make more want to explore more would be to just learn more about enemies. There are already many types of diverse foes in the game but they are not that interesting from an exploration standpoint (Of course, don't get me wrong, from a combat perspective they are quite interesting and fun to fight.) Maybe adding some type of spell that exist for the sole purpose of learning more about the characteristics of enemies would add more depth to the world. This spell could pull up a window with basic things like appearance, behavior, (ex what it preys on etc.) and other random facts.
This could be taken further by just throwing in various creatures that don't do anything other than exist in the world. They could be common or rare depending on the creature. For instance, maybe some creature only appears when creatures from the lava areas begin to migrate into other zones. This would give me some reason to just explore to learn more about Environ.
Finally I don't know if this is even practical but the spell could pull up a detailed drawing of the creature in question along with the other info. I don't know if these could be submitted by the community based on occasional contest or whatever.
I guess the game that really got me thinking along these lines was Beyond Good and Evil and the photography element where you take pictures and earn points (or whatever) when you discover a new creature.
Also congratulations on the official launch and already creating such an awesome game!