Spotted this article recently:

http://blog.hootsuite.com/not-the-manager-type-maybe-youre-a-guru/

It is about engineers and technical staff working in the computer industry but I think some of the ideas could easily be transposed into our situation. Particularly the idea that being good at something technical can lead to promotion in it's own right and not a need to change the nature of what you do.

The central idea is that you shouldn't have to become a manager to make progress in one's career, people management not being the only advanced skill out there (I guess in our industry we could substitute teach for manage). You can instead follow the guru track whereby you gain promotions through developing your skills and knowledge in a technical capacity.

Anyway, read it yourselves if you are interested - there is little point in me regurgitating the whole article myself!

Enjoy.