Molecular Evolution

I remember reading somewhere the idea that evolution is "slowing down" in the sense that the major body plans were laid down very early, and diversification has been within those plans. As time progressed the variation became more and more restricted until we find that now not a great deal happens except for "trifling losses and gains at the species level" What do you think?
Ó 2010 Arthur V. Chadwick, Ph.D.