This worries me too. Within my company I have a pretty good reputation due to experience but I am not famous in the industry so I don't think any leverage I have my with my current company will translate into finding jobs at other companies.
That's a pattern I actually see quite often. People go very high in one company, but when something happens and they leave that company due to layoffs or other reasons they often find jobs only several levels lower and have to work themselves up again.