oncebittern
Steve Sheehan
The Collin's Bird Guide is superb but the gull section could definately do with updating e.g. no Caspian gull, inadequate cover of yellow-legged gull. Of course if you aren't really into gulls this may not bother you. As others have said I'd buy the old one now and buy the new one when it comes out.
Got the book from Amazon - only £10.19, and arrived Saturday. Well impressed.
Funnily enough, I've just posted a gull ID thread...