Jay started out with a look at Diablo and Diablo II, outlining the strengths of the games and what made them unique. Staying true to the Diablo experience has been important for Diablo III - keeping the feel of the previous games while expanding on those core elements.
The heroes will play a large part in the feel of Diablo III, with strong and unique archetypes that will make them stand out. Each character has their own style of play and abilities in order to make their tactics and strategy different.
Ease of play in both single-player and cooperative mode will ensure that the mechanics of the game don't get in the way of the visceral experience. Cooperative games can include up to eight players, and Battle.net will be improved to make it easier to join games and find people to play with.
Changes to gameplay mechanics with regard to health recovery should make the game more tactically challenging. And then there's the monsters, who have been designed to provide some more challenges of their own.
Diablo III looks like it will put up a tough fight for even the most experienced players of its predecessors.