Greetings!
Well, I would say that wide-scale magic would have a few effects;
(1) Magic would probably dominate, but because people never stop thinking, doing, and creating, it would gradually settle in to also expanding and assisting the growth and advancement of technologies.
(2) Initially, it would be centered in the wealthy and powerful; However, over time, magic would make it's way down to effecting, and at least being partially available to everyone. After all, magical ability--arcane or divine, would not be confined to merely one group of people who happen to enjoy a higher economic position.
Semper Fidelis,
SHARK