Why lenses are a more important purchasing decision than camera bodies

It’s not hard to do, what with all the talk about bigger and better megapixels, higher ISO with lower noise and increasingly fast frames per second.  Add to the mix HD video as an option to several models of DSLR bodies and there are enough options to make your head spin.  The result is less focus on the lens and most of the focus on the features and functions of the camera body.  Lenses haven’t changed much over the last few years, so what’s the big deal about?