The Guardian has a tongue-in-cheek article (influenced quite heavily by reading Douglas Adams, I'm sure) on why not continuing to evolve would be a good thing. One of the four points:
1. We're not going backwards. If we're standing still then at least we're not backsliding down the evolutionary ladder, despite whatever anecdotal evidence to the contrary you may have gathered. This is good news. If de-evolution were suddenly to start accelerating rapidly we could all end up as hairy little hominids standing around on all fours in the lobbies of buildings waiting for someone tall enough to come along and push the lift button.