The future Doctor that River describes in SiTL/FotD would seemingly fit this older doctor better than Smith's doctor.
One other thing that I hope changes is the females companions falling in love with the Doctor. Now maybe he will be more of a paternal type like the first 3 Doctors.
They may have also picked an older doctor to better convey the fact that doctor is getting close to the end of his life, if they adhere to the 13 incarnation lifecycle. I would like to think that is the Doctor is starting to run out of regeneration energy that he can not regenerate as youthful as he has the past 2 doctors.