If 'Sheed wants to retire, I'd respect that.
I'd still give him a call come next February and see if he wants to give it one last run.
Don't see how 'Sheed's retirement would really impact the decision on whether or not to bring back Ray Allen. If 'Sheed goes, we're one step further back from contention and one step closer to rebuilding, so why resign Ray in that scenario? Plus, we'd need to pay for another rotation-caliber big man (Sheldon ain't gonna cut it).