Yes, BBC allowed some of the sessions to be released. Sessions from 80+ artists, of the 2,000+ artists & 4,000+ sessions recorded, were released on Strange Fruit Records before closing in 2004.

List of those releases: http://en.wikipedia.org/wiki/Strange_Fruit_Records

List of artists & date of recordings from the Sessions: http://en.wikipedia.org/wiki/List_of_Peel_sessions