We looked at act length in Diablo II and came to some of the same conclusions, "They ran out of time". But when considering it further the intent of the act structure actually got shorter as you went, intentionally rocketing you toward the end of the game. It's one of those things that makes game design hard to relate. It's... it's sort of like a movie score. If done right emotional music can make a scene feel 'better' or raise whatever emotion is being portrayed, but if you start scrutinizing the individual components, or just lose the immersion, it can come off as cheesy.
In any case I think we're estimating a longer game than Diablo II right now, regardless of actual comparable act size.
If the intent was to get shorter as the game goes on, then I hope you guys are more successful at giving the impression of "rocketing [us] toward the end of the game". Act 3 in D2 was such a long, drawn-out process, that the pacing felt like it was actually slowing down before the disappointingly brief final act.
VERY glad to hear that it's estimated to be a longer game than D2! Any word on how much longer, roughly?
The best thing about waking up is the tears. I drink them instead of coffee now.