Limits of Market Action

I've just started reading this article on the restoration of some wetland area in my home state of Illinois: http://www.washingtonpost.com/wp-dyn/content/article/2007/06/23/AR2007062300611.html
and I got to wondering how far the whole "It pays to be Green" idea can go. Surely, there has to come a point when the market will not tolerate anymore greening, provided that greening is authentic, i.e. conserves nature in sustainable ways. I suppose I'm thinking of the market-nature relationship in antagonistic ways-perhaps Marxist-but history has thus far proven the relationship is indirect: economy improves as capital grows, which means the environment (and the rest of us) pays the price via externalized pollution and resource depletion.

But there is low-hanging fruit to be had. Perhaps people/companies (grrrr...) can make money by greening what was once degraded by rapacious greed that is capitalistic behavior. Will such greening at the hands of those corporations responsible for the degradation in the first place be actual greening? Should we trust 'em? Will we fall into a new dogmatic paradigm and continue with the same earth-killing behaviors so long as we're greening someplace, somewhere?