Simplicity, explained in about ~145 slides. Simple is not simple.

A great addition to this explanation would be some discussion about modes.

A few examples they present include: a) a Microsoft Windows wizard experience, b) date choosers that use two separate month and year combo boxes instead of just one combined combo box.

In both cases, you take away control while introducing additional modes, which are invisible states that the user must divine through context clues around the implementation of the user experience. That's partially why engineers can make such truly awful UI -- but it makes sense to them because it matches their mental model.

Wizards encode modes into the fixed, rigid "choose-your-own-adventure" style of navigating seemingly disconnected questions that don't connect me with what is really happening. (GROSS!)

Ultimately the most telling slide is the one around progressive disclosure -- hide things where people will find them.

As an aside, I've been quite impressed with how Slideshare and Scribd have made Powerpoint docs super accessible. It's simply unprecedented how easy it is to absorb information in bite-sized chunks from such beautiful and well designed presentations.