First off for those of you who haven't seen it. The first video was unlocked in Blizzard's develop video's for Diablo III, and here it is
The main points of this video are interesting. Why? Because they say that the game is pretty much complete and are just working on polish. Also stating that they hope to have it out by the end of the year. Why would they release such a video knowing that someone somewhere would go off on them on their forums?
Well the answer to that is simple. They want people to talk about the game, they also want their audience to know what happened or at least want them to know parts of what happened so there is a reason the game was delayed over 5 months. They're trying to get you interested in the story of how the game was developed and this is a great hook. They want you to be asking, "If they were talking like this over a year ago, what happened?" So don't be raging like crazy because they didn't keep to the little internal deadline they set themselves. They want to give you a glimpse into the development process of a game that may very well be one of the best if not the best ARPGs there will be.