We are actually working on one project which will be a low volume in production, and production is going to be using 3D printing.
To save time and $ we start ignoring typical injection molding “rules” and design some parts that cannot be manufacture by any method other than 3D printing.
We create some closed chamber parts, which with injection molding we will need two parts to achieve what we can with one printed part.
http://www.thefiscaltimes.com/Articles/2013/03/06/3D-Printing-Could-Grow-to-Over-3-7-Billion-by-2015.aspx#page1