Perfectly adapted for controllers, and STELLAR couch co-op.
After watching every available minute of online preview videos, and with a strong desire to have a new same-screen "couch co-op" game to play with friends & family, I reluctantly pre-ordered Diablo3 360... and thus far it has proven totally worth it.
The aim-highlighting and left-trigger lock-on mechanism works beautifully with ranged characters. The drop-in online multiplayer works as seamlessly as the multi-profile same-screen gaming. The graphics resolution understandably had to be lowered, but the action is smooth as silk. Audio is likewise great, and retains the fine-tuning available in most PC games (music vs effects vs dialogue vs ambient; usually missing from console ports). Category-based inventory management & shops are a bit bulky-feeling at first, but it works well after just a few minutes of play.
Excellent work, Blizzard -- a good job (albeit via unexpected means) of earning my trust back.