The BBC coverage of the Edinburgh Festival today included an interview with Berkoff about On the Waterfront.
(http://www.iainfisher.com/berkoff/berkoff-on-waterfront-2.jpg)
Good news, you can see it here:
www.bbc.co.uk/cultureshow/videos/2008/08/edinb_s5_e1_waterfront_extra (http://www.bbc.co.uk/cultureshow/videos/2008/08/edinb_s5_e1_waterfront_extra)