Two real takeaways from this short, on-stage commentary by designer Philippe Starck: the placement of the Kindle's buttons on the side means that the first time you hand it to someone, they almost always turn a page accidentally; that the designer was unwilling to disappear from his design, determined to make his mark visible in the final product.
The former criticism is valid, I think, but only for that particular scenario. Unlike some, I've found the Kindle's large page turning buttons on the side to be very well placed and comfortable to use in a variety of positions. (I do question why there is a need for a "Back" button on the right hand side that performs a different function than the button on the left that flips back a page.)
The shape of the Kindle itself is actually growing on me a bit. It's clear they wanted to try to create a shape that was iconic, and the shorn corners do make it slightly more comfortable to hold, although I'll concede they are mostly gratuitous negative space. The main problem with the Kindle's design is still the keyboard, which while usable, is not needed at all while reading books. Future versions should stash it away or make it virtual.
To return to the former issue of accidental button pushing, I've found a very similar issue with the Rock Band controllers, even for seasoned players. Because the most natural place to grasp a guitar controller is on the neck right under the headstock, exactly where the buttons are, accidental button presses are common when handing off the controller. Worse, when trying to get four people synced up on the screen, where a single button press from any controller can take you back to the menu or hold up the menu selections, it's far too difficult to get everyone playing. (And besides accidental presses, the longer it takes to get into a song, the more likely it is that someone will absentmindedly hit a button while warming up.)
That's less a hardware design flaw in Rock Band, though, as it is evidence that there needs to be a "Band Leader" mode that either locks out the other players' input until a song is selected, or locks the fret inputs to force players to use only the directional pad on the guitars.