The time will come when smart phones will become mainstream.
The question still remains.
Will we be able to built-to-suit?
Notebooks are limited in the parts that can be customized. Therefore, smart phones may also become the same.
For example, notebooks can have their CPU (processor), RAM, DVD drive and hard drive changed. Unfortunately, there is not much else that can be done.
Although, I do not think anyone really cares if their smart phone has a Nikon, Samsung, Kodak or some other brand of camera in their phone. As long as it works.
A company that sells custom Android smart phones. Well the selection is limited at http://synapse-phones.com/