I agree that personalized weapons and characters are a great idea, but you also need something to DO with it. Right now the game becomes a little repetitive after the first ten hours or so, and even more repetitive after the level cap.
Give us goals, expansions, plots to unravel — something. You have a great setting for some really in-depth stories, especially with the random events on the map. They need to over-arch at some point and form an enthralling story, even if that story is totally of the players’ choosing or on the player’s terms. It will keep people coming back, and give them challenges to test their hard-earned mercenaries on.