Do we need Wolverine?

Wolverine's appearing in a whole host of Marvel comics, and is an official team member of three separate X-Men squads. He'll soon be joining the new Avengers team and in his ongoing series, Logan's working for SHIELD. We all know that Wolverine is one of the most popular comic characters and his appearance in a book can boost sales. But do the X-Men need Wolverine? Or rather, does every X-Men team need him? Joss Whedon is using him quite well in Astonishing, and Austen, Milligan and Claremont have yet to do anything too great with the character in their respective books. In the early 90's, the X-Men were divided into the Blue and Gold squads, and the Gold team was Logan-less. If Marvel were to limit his regular appearances to New Avengers, Astonishing and Wolverine, would X-Men and Uncanny get spanked, sales-wise? It's something I've been wondering, as Wolverine's been a mainstay of the team since he joined, and the X-Men books are usually the top the charts.