My father is a pro photog as well, and had a similiar experience with the 5s. Its handiness combined with its quality is striking.
He uses it for location scouting and whatnot, then returns with his gear and shoots with the big beast.
Yup, now anyone can take professional print photographs.
This will make the "photojournalist guild" that makes up a short list of the go-to photographers for any mainstream media even more exclusive.
I'm sure they'll make up more arbitrary standards and rules to keep others from entering their faux exclusive assignment list. If there isn't a rule banning the use of smartphone cameras, I'm sure one is in the works.
Know one that tried to sue these guys for not letting her in on their assignment schedule. Came down to the process server could not identify anyone in jurisdiction who claimed maintence of such a "list" or if this list even existed.
She just could never get any assignments while having the talent to take the photos. Her career ended up teaching in colleges for lack of finding professional work.