I think that's why a lot of people drop off... investing time in things that die. I guess that's about not putting all your eggs in one basket... get an awareness and loose understanding of several things. Things like when to use newer ways of storage and why (i.e. document storage or blob storage if your not already). Don't necessarily need to become a guru in a specific thing, just be able to avoid risks of obsolesence and identify opportunities that could be looked into further if the business wants/needs to.

I got caught out with silverlight as well btw :-)