The future is clouded
In the age of virtualization, generalists should be forced -- or force themselves -- to specialize in a current problem. Specialists, on the other hand, need to be pushed (or voluntarily extend themselves) outside their area of specialty. The old truths of data center operations are falling away and being replaced with something new. Not suggested here but a experience that would stand both generalists and specialists in good stead: learn operations in the public cloud.