Deciding on my next Career

Currently I am giving a lot of thought to what the next part of my career should look like. I have always done this from time to time, and the time is right for me to move on from my current position. (Right now, my role can best be described as a mix between Application Architect, Lead Developer and Scrum-master).

Anyway, I got to wondering about how sustainable a career based on Lean and Agile will be. More specifically, I wondered:

Is Lean a one-time improvement that companies can make, and then once they "get it" have it be self-sustaining, or is it something that needs constant fresh input?

Articles like When the Low Hanging Fruit Disappears... Sustaining Lean for the Long Term imply that it remains hard work. You can successfully implement lean, but it remains a process that requires constant gardening to keep in shape.

It is touched on by the previous link, but this pdf article specifically points out that lean gains can be very short term (6 months) when employees do not completely "buy in" to the approach. This leads to the theory of "critical mass" for lean - you must have some critical mass of people that "think lean" in order to have a "lean culture" that can sustain itself.

Lean leadership (pdf) is an interesting participant. I've stayed away from management roles in my career, and in so doing, I've come to realize that I can lead without being a manager. Perhaps that sounds obvious, but many people think that that leadership requires authority. This is simply not the case. If someone has a compelling vision, the ability to communicate that vision, and the competency to back it up, then people will share that vision and help to achieve it.

Getting back to my original question...the consensus answer seems to be that lean is sustainable, but it requires appropriate leadership and a new culture. Involvement throughout the organization is required in order to apply the necessary continual adjustments and improvements.

In my own career, I'm leaning toward a more formal leadership role in software. Not as a manager, but in a way that allows me to exercise my skills in a way that can cross internal organizational boundaries. The best fit I can think of right now is Enterprise Architect.

If anyone has other ideas, please let me know.