That is a good article, Doc.
Garfish, if your link-building techniques consisted primarily of directory links, then your rankings are probably toast. Google has had an emphasis on quality link from sites within the same industry for a couple of years.
Their next target may be all of the tens of thousands of crappy directories out there. All they have to do in de-index them like they did to some of the major blog networks.
"It's inexcusable for scientists to torture animals; let them make their experiments on journalists and politicians." -Henrik Ibsen