Some thoughts - something of a rant, but interesting:
Engineering is built around figuring out how to do things, around solving problems. It's about making progress by discovering as many wrong solutions as you need before you find the right way. You try something, and then you find out if it works. It may take minutes or hours or days or weeks to see the results, or even seconds, but that delay is what separates engineering from art.
In art, you experiment and discover not to find one solution, not to document your mistakes, but to build your own internal, intuitive knowledge, to become fluent in the space of a system. Then you have the potential to create. It's about bridging the gap between intention - directed from within the self, not by a person or institution - and manifestation. The painter studies and practices and learns the characteristics of paints and brushes and surfaces, not in order to compile a manual or to solve a problem, but so that when he wants to paint something, he'll be able to paint it.
It's the difference between a slide show and an animation. It allows for that spark to appear between the frames. Once you are there, once you are fluent and exploring a space, with all the technicalities subsumed by your mind so you are free to create rather than to simply solve, then you are in the realm of design and artistic expression.
Oh, and if Daniel Pink is right, then engineering is also what may become automated or outsourced. I'm sticking with art. :p