I think we may be set at S for the foreseeable future.
Bishop will be the full time starter and has really developed into a playmaker. IMHO, the ceiling for him is very high and the trajectory is clearly pointing straight up.
Right now, Poyer has helped immensely in Bishop's development and I think Poyer is enjoying this ride. He still has the skills but I read a couple weeks ago he believes this is it for him. Maybe he retires and becomes a coach next year. He would be very good at it.
Opposite Bishop, I can see the Bills moving Taron from NCB to the other S this offseason. Hancock will be the backup.
IMHO, Taron would be an excellent S. He is a sure tackler, good in coverage. May not have the same fast twitch reflexes from a couple years ago (hence the move) but he is smart and knows the defense.
With Hairston and Benford at boundary CB, we need to find another NCB in the draft. I do believe our secondary will be a major strength of this team next season.