Well, I think this is just a publicity stunt.
http://www.dailymail.co.uk/sciencetech/article-2515747/Motorola-start-3D-printing-modular-mobiles-customers-like-Lego.html
No not a stunt but it is definitely more of a research project and will continue to be for quite some time even well after it comes to market, assuming that it does. Then again publicity stunts come in all shapes. Take the new screens they are talking about that wrap around the edge of the phone. This contributes to the phones functionality in only a very trivial way while raising questions regarding durability. Such a screen would be at far greater risk of damage since it now includes one of the edges of the phone. This causes a lot of hype though because it looks really sleek. I’ll be impressed when I can unfold my phone screen to get a bigger view.