This is a response to Sixen from DiabloCast episode 22, but is a general point open to all. There has been some discussion about Inferno and whether or not it makes for good "end-game" content. Sixen suggests that it is not true end-game because Inferno is not new content, merely another difficulty. He issued a challenge, more or less, to listeners of the podcast to discuss this issue.
My question is this, and it is somewhat rhetorical, but is worth some thought I think: Why does there have to be any end-game at all? Whatever happened to beating a game and saying "Man, that was sweet," and setting it down. When did that stop being ok? Video games are akin to books and movies in some regards, and everyone knows going in that a book or film will end and you walk away. Diablo 3 is not an MMO, which are intentionally open-ended to some degree. Why, in the opinion of Sixen and/or the populace here, must Diablo 3 have end-game content at all?
Some games that is very true, they are built to be played start to finish, the end (Bioshock, Half-life, God of War, to name a few of my favs). Games like Diablo however, are meant to be played over and over and over, that's the fun in it. The constant leveling of different characters, finding the perfect items for a certain build, and sheer fun of making giant demons explode into a cloud of death. Like many people have said in this thread, the game content in itself, is the end-game. For some people, finding unique areas/bosses only in inferno (good idea), would be end-game content. It is different for everyone, but in the end, it's a game that is not meant to be over after one play through. Not just, start to finish.
Edit: But I can agree with Sixen because the type of end-game content in Diablo, is not like the end-game content in a game like WoW; where you finish leveling then raid, aka something ENTIRELY different than just a flat, insanely hard difficulty.