There’s an interesting discussion going on at Leiter’s blog and on Certain Doubts about Dreben and the history of analytic philosophy. I recommend especially Jason Stanley’s comment on the Certain Doubts post.
While on the subject of Dreben, I thought I’d point out something pointed out to me not too long ago by Bill Tait. Dreben is commonly credited with discovering the (now well-known) errors in Herbrand’s Thesis. But these errors were actually discovered by Peter Andrews in 1961/62 (he was then a grad student at Princeton). Andrews has a full account of the discovery and the correspondence with Dreben in his Herbrand Award Acceptance Speech.