Adaptive Systems.. aka Adaptive Websites
If you build a website for consumers that can only be viewed in one way on one way you are going to need to redesign within a few years. With the growth of the mobile web these are going to be important principles going forward. B2B probably has a long end out before these “adaptive issues” become a concern. B2C’s don’t panic if you don’t fit this right now, but I would start socking away some cash to make your website adaptive.