Why Internet-connected DRM fails the customer
The short version: Diablo III is a prime example of why always-connected DRM will not work in the long run. It protects the supplier's interests while turning customers into enemies.
Sure, you can guarantee that people aren't pirating your game. But by the same token you are going to lose sales because your game has onerous requirements: if the game is running on a server in the USA, it won't be playable in Australia. If the game regularly goes down for maintenance at 12 noon in California, that's prime gaming time in Australia.
So far my experience with Diablo III has been two hour-long sessions of actually playing the game, with over 40 hours accumulated "playing" time. I have spent another 20-odd ours waiting for the game to be available to play. In the meantime Torchlight and Torchlight 2 have been available any time I wanted to play them.
Thankyou, Blizzard, for raising people's awareness of the issues that customers will face in future instances of "Internet connection required to play this single player game" style DRM.