One suggestion: Make it slightly delayed, using a Timer, so if your users want to edit three items in a row they don't have to scroll back each time. It should also *not* re-sort at all while an item is being edited. This is indeed much better from the usability point of view, although it does entail figuring out when the user is editing an entry, which I am currently blissfuly ignorant of (I suppose one would do this via the textfields' delegates or the appropriate notification)
One suggestion: Make it slightly delayed, using a Timer, so if your users want to edit three items in a row they don't have to scroll back each time. It should also *not* re-sort at all while an item is being edited.