I got in touch with Blizzard shortly after the auction house news broke, and here’s what a rep told me:
“We do not have plans to implement an offline mode. While the always-online requirement made the auction house possible, the auction house was never the driving factor in our decision to make the PC version of Diablo III require an Internet connection. The game was built from the ground up to take full advantage of Battle.net, which provides a number of important benefits, including persistent server-side character saves, a seamless PC multiplayer experience, cheat prevention, and Real ID and BattleTag social features.”
So basically, same song, 572736528th verse. And while I understand Blizzard’s desire to enable a strong multiplayer environment, I don’t think that precludes them from giving people the option to play as they please – especially when the current requirement makes it downright impossible to play in many situations and environments. The online community won’t suddenly flee to the darkest corners of the Earth, hugging only the shadows of their reclusion, simply because they don’t have to play with other people all the time. Cases in point: a couple little games called Diablo I and II.