Ok, lets see. The languages that I have seen come and go as intense fads:

  * Easel
  * Telon
  * Powerbuilder
  * Codfusion
  * CICS (was actually taught in a "CS" course not too far from here)
  * PL/I (may be not totally dead, sadly)
  * IITRAN (maybe not that intense)

To Tom's point, I know of a project involving 300 Telon programmers who had to be let go when a massive project failed. Few who invested in the above technologies are working in them today.

More importantly than the article says, develop skill in solving business problems using your programming skills.