You know what I'd like? A game that deals with armor encumbrance realistically.
You'd travel with pack mules for your stuff and only wear and carry gear appropriate to the circumstances. This would make room for a much wider range of viable armor for different circumstances, and open up possibilities for interesting tactical gameplay; for example, ambushing a group of enemies who are not prepped for battle - i.e., have their battle armor packed up for transport rather than on their backs, and are unarmed or only lightly armed - would give a real advantage. Being at the receiving end of such an ambush could make for interesting challenges too.
Naturally the UI would have to accommodate for this, letting set up different armors and carried inventories e.g. for city, bushwacking, or pitched battle, and switch between them without having to manually click-n-drag every piece of gear. So you'd wear light leather armor form wilderness scouting or caving, ordinary clothing with maybe a dagger hidden in a boot for the city, and your best and heaviest armor if you were girding your loins for a pitched battle.
I'd be surprised if P:E was the game to actually do this; it would very much break with cRPG convention and the "Infinity engine" inspiration, but one can always dream...