You should always be aware of industry trends to stay employable, including learning what skills recruiters are looking for. You are always one management change away from a reshuffle.
As a person working in the IT industry for more than a decade, being intimately involved with several major Open Source projects in demand, it sounds debatable (perhaps even wrong), as many in demand skills last longer than fads (eg PostgreSQL clueful-ness).
So, what you're saying doesn't sound right to me. :(
Thoughts? :)