Following in the footsteps of WoW's pre-expansion patch, Diablo 3 will give the community quite a bit of stuff for free. Blizzard Community Manager Grimiku explains:
The new Paragon system will remove the Paragon level cap (meaning you'll be able to, well, infinitely level your toon), which is good news for the few and proud that have reached the max paragon level. There'll also be other changes Paragon 2.0 will bring, and we'll get those then too.
The Loot 2.0 vision for Diablo 3 will be especially important for those that want to get characters ready for the expansion. Loot 2.0 means that the gear drops you get will be more focused on your current character, which means that in general, gearing up should be easier; and that there should be more 'reward' for playing the game.
The other features Grimuku talks about, the Loot Runs and the Nephalem Trials, are end-game modes/activities.
Blizzard seems to be taking a new direction with Diablo 3, addressing some of the fan complaints. No matter what your feelings on Diablo 3 are, this will certainly be interesting to watch.