Your best software developers are not the ones you turn to for everything. Your best are constantly distributing knowledge, removing themselves from being a key-man dependency. Your best have delegated sufficiently that they have freed themselves up to learn new skills.
It is a natural instinct for software developers to want to learn more, to consume all of the knowledge in their vicinity. Like a sponge growing heavier the more it soaks up, it feels good to become the owner of more knowledge. This applies to good software developers anyway; you can spot the bad developers a mile off as the ones who have closed their minds off and don't want to learn anything new. I know what I'd do with a sponge which refuses to soak up anything new.
It is a natural instinct for software developers to want to learn more, to consume all of the knowledge in their vicinity. Like a sponge growing heavier the more it soaks up, it feels good to become the owner of more knowledge. This applies to good software developers anyway; you can spot the bad developers a mile off as the ones who have closed their minds off and don't want to learn anything new. I know what I'd do with a sponge which refuses to soak up anything new.
"Find the most talented person in the room, and if it's not you, go stand next to him" Harold Ramis