Chuck - I've had two copies of the 18-55 IS and the 17-40, and never has the 18-55 "blown the 17-40L away". In fact, the 17-40L beats it. You can see the pics for yourself:


http://camerablognetwork.com/2009/05/canon-17-40-versus-18-55-is-comaprison-revisted-post-canon-50d-af-micro-adjust/





In fact, the 18-55 Is had a nasty purple cast and did not replicate the color accurately.