Did you see Computer World's, "The top 10 dead (or dying) computer skills" published last month? Some have been on the list for some time, such as Cobol -- it's needed just long enough to finally get companies off those legacy systems. What surprised me is even the mention of non-relational DBMS and non-IP networks. I guess I'm a bit ignorant in the fact they these two still exist in places.
Then there is the more obvious, Cold Fusion. Of course with open source solutions and better scaling solutions, Cold Fusion is on its last legs. I remember when it was a good choice, because the open source alternatives and Microsoft had not matured; now, if you're not a Microsoft shop, you're probably using open source.
What other skills do you think are on the way out? How about a Microsoft desktop OS? Is there life after Vista, or did Microsoft make it easier to look at Apple or Linux? And of course the PDA -- it's all smart phones now.