As it's been mentioned before, it'd be nice to have some tasks which require collaborative efforts, like players to be able to construct something permanent together from different parts they have found or to change landscape, say, to open a way to a new continent or make an entrance to some underground cave system
I would love to the see the library like that VOX-System from Time Machine back in 2002. With guided predifined tours through history, maybe even with full animated sections where my avatar gets set in the middle of action of critical historic incidents, sort of live viewers viewpoint. Would be cool to walk around in some parts of Arkadias key history sequences, which would be the ones we have in the storyline. Or through the eyes of passive witnesses of the incident, sort of. Hope you get the picture, I got it in my head, but haven't the words to match it properly