There’s an interesting development in the beta for World of Warcraft, which I think it pretty much the solution MMO’s need in order to not lose the interest of casual players (like myself).
It’s called the “rest state.”
Basically, what it does is that it gives those people who are not logged in for long stretches of time a leg up on gaining experience through PvE combat. As long as you have rested (either by being at an Inn or logging off) for eight hours, you receive a bonus to your combat experience for a set amount of time. After that point, it drops off until you are earning normal XP, until you are no longer earning any.
It’s a good way to balance out level grinding through combat instead of quests and crafting. I would suggest that any of my MMO-playing friends should read the patch notes and see about it - it seems to be a relatively ingenious way to solve the powerleveling problem inherent to the system of MMOs. And, it appears that it will encourage players to have multiple characters on one account for maximum leveling ability, which is a good effort.
Now if they can add a PvP element to rival that of Dark Age of Camelot, I’d be completely sold on WoW.