Actually, EXP is something we're going to be talking about next time, but neither fighting nor exploration are going to be directly giving EXP soon. Instead, it will all be based on helping NPCs with their hopes (the game's equivalent of quests), OR by taking care of "implicit hopes" such as destroying a den of bad guys, or a named bad guy.
Basically, small monsters are not something that are particularly notable; they are rather like Zelda monsters in that respect. They might be a formidable challenge or not, but you don't need to fight them just because they are there. I always wanted that to be the case -- and for the freeform exploration to be the case, too -- but as soon as you start attaching EXP rewards to that sort of thing, people start feeling like they have to kill everything and explore every last nook of every map. It encourages grinding, in other words; and all but eliminates the possibility for stealth of any sort.
It's also one of those things that is near impossible to balance since the civ level and exp is shared between all players; it makes the co-op experience either one of lightning-leveling, or one of each player's contributions being diluted based on the number of players on the map. Neither of which are fun. But even in solo adventuring, it screws with the ability to set your own difficulty level by which regions you go into, etc, since just grinding monsters a few levels up would be way too big a payoff, etc, etc.
In short, it's just riddled with issues to give out EXP for small things in this game. It encourages OCD behavior instead of freeform play, and it messes with the larger subsystems that are unique (or uniquely combined) in this game.
BUT, that's not at all to say that EXP is going away. We're just shifting it to being doled out in larger doses rather than tiny ones. As you complete meaningful activities, EXP is gained, and that's it. That's not to say you have to deal with NPCs now -- you can still murder everyone you meet as soon as you meet them -- but if you do so your EXP gains will have to be based on solo adventuring and handling implicit hopes -- destroying monster dens or killing named monsters are one, possibly finding legendary artifacts or something also might make an appearance, and whatever else we think up. We definitely want to reward more than just combat, even if you avoid NPCs, so we'll see where that goes.