There is legislation pending that will profoundly change patent law in the US. The US has had a different policy than most of the rest of the world. Ace of Spades dicussed this:

...Yet, what may be the most dramatic change of the pending legislation is the shift from a "first-to-invent" to a "first-to-file" criterion for issuing patents. At present, even if a patent has already been filed for a particular invention, another inventor can win the patent if he can successfully demonstrate that he invented it first. Passage of the patent reform bill would award a patent to the first person to file for it, thereby eliminating a time-consuming court process...

In my experience companies liked to publish information on inventions that they don't want to spend the time or money necessary to patent to make it impossible for anyone to patent something similar at a future date. So, if this legislation passes, will there be a mad rush to file on all of that prior art? My guess is that there will be; after that there will be a lot of court cases. I doubt the patent attorney's will be put out of business.