[bduerst]

The BLS has this documented fairly well over the past century: http://i.imgur.com/BPNyjM8.png

As advances in agricultural automation removed laborer jobs in the 1900s, workers switched to different, more-specialized industries.

In short, we will probably see jobs disappearing because of automation in the 2000s, but it won't necessarily be bad. Most likely we will also be seeing many new types of jobs appearing as well - some which may have never been conceived yet.