http://brucefwebster.com/2008/04/11/the-wetware-crisis-the-d...
I think the NetFlix strategy is partly a response to this.
People pretend there is a 10x difference between programmers. I assure you that is way too low. The difference is actually Infinite, because contributions can be negative (I've seen a bad programmer set back a project by 6 months). Even worse, a programmer can create a toxic atmosphere, causing good programmers to leave.
I like the NetFlix strategy. Some people are just a hell of a lot more productive than other people. (Example: http://bellard.org/ )