Blizzard’s Mike Morhaime laid bare plans to expand on Diablo 3 in a recent open letter to the community.
We’re also working on a gameplay system that will provide players who have max-level, high-powered characters new goals to strive for as an alternative to the “item hunt.” We’re not ready to get into specifics just yet, but I can say that we’re actively taking your feedback into account as we plan out the future of the game.
This is in addition to “useful Legendary equipment, improved skill balancing, user interface upgrades and PVP arenas”.
And now the bad news for offline single-player gamers.
Diablo III was designed from the beginning to be an online game…the always-online requirement is the best way for us to support that design.