almost every rpg without pvp fails. d2 was successful for numerous elements but its trading and pvp were the main ones plus the community attitude as a whole.
Wow... in my opinion, this statement is completely wrong.
Take a look at any given list of RPG games (here's a huge one, for example). Aside from MMORPGs and maybe ARPGs, the overwhelming majority of RPG games and its sub-genres are single player games or at least focused on single player, and if they have multi-player it's oftentimes co-op. I'd say PvP is rather an exception in this genre, or at least not a given. It's only in recent years that every single game developer feels like "oh we need PvP because it'll give us $$$" which has lead to a video game landscape that is more boring than ever before. But still many recent RPGs do not have PvP.
That aside, we had the discussion "PvP or not" recently and most of us agreed that PvP right now seems to be further away than ever for Diablo. It currently just doesn't fit at all - it'd break the game if they'd change skills and mechanics just for the sake of PvP, and that's unlikely after all the years of tweaking just to get a somewhat stable PvE experience. What we concluded though, as a possibility, might be the PvP/PvE mix that was on the frontpage a few weeks ago.
This game was created to make PvP for god sake, not PvM again and again !!!
No, the game was not created to make PvP, it was created for PvM again and again. One of the developers said in one of the playtests that due to all the overpowered legendaries with game-breaking affixes that "real PvP" would be incredibly difficult to implement at the moment. In the immediate future, I see no PvP being implemented. Diablo 3 is mainly a PvE game.