@property definitions with ARC: strong or retain?
1) Shouldn't retain now be replace with strong or weak?
No. You cannot replace retain with weak; they are different. And strong is a 100% synonym for retain; they are identical. You can use either, so there is no "should" here. You can replace retain with strong if you like, but you don't have to.
2) Why does the auto-generated code still use retain
Why not? See (1). retain is correct so there is no problem.
3) What is the correct replacement for retain in this property statement?
There is no need to replace retain.
I'm currently debugging a problem using NSFetchRequest, and I thought this might be the source of the problem. Thoughts?
It isn't.
To answer all three questions in one: retain and strong are synonymous with each other, so both are correct. The documentation states
retainimplies__strongownership
strongimplies__strongownership
Before ARC, you have to 'release' an object which is retained. That mean retain has counter part. After ARC you don't need to release. So use strong. Its a visual clue that you don't need to call release.