I don't know that Curt Schilling will ever pitch again.
That certainly clears up the "problem" of having a six man rotation. Beckett, Matsuzaka, Lester, Wakefield, and Buchholz are a pretty good staff. They'll need Julian Tavarez again this year, because there's no way that Lester and Buchholz make 35 starts apiece. Tavarez isn't a bad option for a spot starter.
It wouldn't surprise me if Schilling came back for the last couple of months. Between Wakefield, Lester, and Buchholz, they'll need a new arm then anyway. I don't know if the Sox will make the post-season, but since I think Schilling is a borderline Hall of Fame guy right now, another couple of good post-season starts would help his case considerably.