I'm a little premature for this, at 35 I am a CTO that still manages to write some code when I'm not distracted by Q&A sites, interviews, budget sheets, pending litigation, that black hole called the US Patent office and other things.
I first learned the 'business' end of programming when I got sick of working for other people. I was familiar with some aspects of administration, such as software licenses and contracts in general so it was a natural move for me. Quite frankly, I hate it.
Currently, I'm well versed enough to continue to not only keep pushing neat products out the door, but also ensuring that we keep and maintain people who can push neat products out the door. I also try my best to steer us away from legal pitfalls. I refuse to stop writing code, so it is indeed like working two full time jobs.
My goal? Make enough money so I can just go back to pushing neat stuff out the door, without having to worry about anything else. That probably won't happen for another 15 years, which, remarkably, puts me at the same age that you raised in your question.
You also have to consider that most (good) companies take a different look at management. I would not, for instance, interfere with a project that I knew nothing about even though my title 'entitles' me to do so unless there was some compelling reason to do so. If you are going to go through all of the hassle of establishing a 'senior' level and then short circuit it, what's the point?
Where I work, if you are able to come up with an idea, draft a spec, a plan and a budget, you own it, it's your baby and you are free to spend money and run with it with minimal oversight.
I think most sensible companies are realizing that they make more money when they (within reason) put people at what they want to do. Manager today, grunt tomorrow, consultant the following week. As long as the compensation reflects your responsibilities, I don't see how a title makes any difference :)
Footnote: I hate software patents and am a member of the LPF (league for programming freedom)