In that a client feels having an old copyright date displayed in the footer across a site will have a negative SEO impact? My opinion is that it should make very little difference SEO wise and should only change if a substantial change has taken place with regard to the design of the site.
I have done some Googling but have not come across anything "concrete" any pointers or if you have had experience changing from a static to a dynamically change year and the effect it had that would be great.