There are two terms: The highest and best use, and the greater good, each mean something utterly different than most lay people would expect. The first term refers to monetary value. Thus, the highest and best use of a forest is to log it to extract the highest monetary value from said forest; another example would be to raze an old home and replace it with a new more expensive home, condo complex or shopping center.
http://www.google.com/search?hl=en&lr=&safe=off&oi=defmore&q=define:highest+and+best+use

The greater good is often interpreted as the actions of a governing body acting on behalf of its constituency.
http://www.usatoday.com/news/opinion/2005-02-21-condemnation-oppose_x.htm

If a ruling favors the expanded definition of eminent domain, most properties will be in peril. There are many tracts of undeveloped lands privately owned to maintain their natural state. Will this ruling pierce those privately protected lands?
http://natureconservancy.com/