I was wondering how hard of a job it is to pick up, and maybe if someone followed Kelly's career more closely than me. Just a quick browse of Chip Kelly's Wikipedia page, and it seems like he has never officially been credited as a QB coach.

Kelly played as a QB in high school, transitioned to DB in college - then started out his coaching career on Special Teams/OLB in 1990 before moving to offense (RB/OL/OC) in 1994. Since 1999 onwards, Kelly has only been credited with being an OC or HC. 

I am ecstatic about the hire, and think it is a clear home-run, big-time get especially this late in the coaching cycle. Kelly is likely a better equipped QB coach than Corey Dennis, but I wonder if Day will trust Kelly enough in the QB room to let him take the lead fully with that position group.