The skill thing isn't a very fair comparison, since you were skill locked and couldn't respec which left you having to build to the small subset of builds that could work all the way through hell. Now you can consider what you expect to work with what you are about to encounter and build towards that, making niche skills viable.
I think that D2 needed to better balance the niche skills, but D3 drops the ball with the rune system.
It really doesn't go far to push samey builds, and despite Blizzard's deceptively generic statements from my experience I have a hard time believing that people are doing much of anything.
It was posed that Inferno's secondary purpose was to find and see the broken builds as they arose via people rocketing through this near-cheaply difficult mode.
