The Diablo 2 Cowlevel was a big mistake, this is a personal idea. It was a fast way to gain experience and gold and almost ruined the game. Here is what Bashiok said when asked about the Cowlevel and the plans to bring in in Diablo3:
Yeah, who doesn’t like fighting cows running around with halberds?
I disliked the secret cow level from a design standpoint though. It actually angered me that it existed at one point, maybe it kind of still does.
I’m not a designer, at all, but in my opinion and from a design standpoint I think the secret cow level was a failure. For a long time it was one of the most lucrative ways to level, and one of the best places to MF. For an easter egg, something fun and whimsical, to overshadow the entire rest of the game was a huge problem, and one that existed for far too long. It was a fun idea, a cool nod to the rumors that spawned it, but in execution it was just… game breaking in some ways.
Indeed he speaks great words. There is no room for that idiotic area in Diablo3
A game should be played not leapfrogged by stupid maps. Some fans actually liked that level and will not be pleased to hear that the Secret Cowlevel WILL NOT exist in Diablo3