Why do many of you people think this is a bad idea?
Seriously, you guys are so negative about this when there's nothing wrong with it. The phone can't really suffer from bulkiness when there are microprocessors, flash memory components, and compact camera lenses. Dropping the phone should probably not be a problem either because the components will probably be <$100, but dropping it shouldn't be a problem anyways because the developers would probably make the pieces secure with a screw or something. If you ask me, this idea would work well. Now all that they need to do is make the phone more modular, because the grid on the back of that phone seems too restricted.
TL;DR Just read it. ^