Mark Simon reported in Medis Posts Search Insider (12/02/2007) that the search engines would be the death of SEO. The logic behind this arguement being that as the search engines advance even futher in the way they read and index web pages the more the tactis used by SEO companies will become irrelevant. They will eventually be so advance in their algorithm that they will pull the website which is most useful to the user regardless of the sites tactics, and maybe even content.
Im not sure I agree with this arguement but I do agree to some degree that search engine optimisers will need to become experts in usability and functionality of a website rather than content. Navigation will become increasingly important (even more so than today) as will display and ease of use. Elements such as download speed become more prevelant and the basic rules of SEO as we know today change. This nothing ground breaking but is something to consider when making recommendations for websites. In the future the basic premise will be, make the site user friendly and you will make it search engine friendly.