As to my own experience, I made the leap (for the second time - the first time was a mistake) in my late 30s and never looked back. And being (say) a development manager can be a very rewarding job: teams of any size do take some organising (do it right and they'll even thank you for it!), people need support in their career development, and it takes someone who cares about technology to make the decisions to invest in things like testing, to sell the big refactorings and so on.
To put my age in context, I had always been a developer, but by then I was in my third industry (aerospace, tools, finance). Now at 44 I'm leaving behind a big budget team in a big enterprise to become an IT Director in a small but growing company. Smaller budget but bigger scope, and the chance for the first time to have peers and a manager that aren't in IT, which makes for a very different challenge indeed. To someone who is always learning, dispensability is something to pursue!