Diablo 3 uses an isometric camera like its predecessors. The development team considered using a "more modern" camera for the action RPG but director Jay Wilson said he rejected the idea.
"Very early on in the process we had some people who argued that we should not make the game isometric, that it would be better technology, more modern, if we made a third or first-person game," Wilson told games.on.net. "I really would have nothing of it. For me a camera is not a technology choice, there's more than enough first and third-person games out there."
A first-person camera would've been pretty shit, to be honest. First-person just doesn't work too well with hack-and-slash games. It's the reason that Skyrim and other Elder Scrolls games have very iffy combat. It makes your attacks more precise but being locked into such a limited FOV makes it hard to fight groups of enemies. The end result is a lot of button-mashing and circle-strafing.
Third-person cameras work better for action RPG's but still doesn't seem like the right fit for D3. Diablo games pit players against huge hordes of enemies. It's a lot easier to see the full battlefield, including all their friends and foes, with the isometric camera. It allows the player to be a little more strategic. A third-person camera requires the player to focus simply on the enemies right in front of them.
Still, some series have made the transition to full 3D successfully. Legend of Zelda: Ocarina of Time, the first 3D game in that series, is arguably the best of the bunch. If and when Diablo decides to ditch its isometric roots, I'll be one of the first to complain but Blizzard could find a way to make a new camera work.
D3 will launch next week worldwide. Analysts are expecting it to sell well even though it doesn't have a "modern" look. Considering people are still playing D2 to this day, I can't disagree with their assessment.