Eminent Domain is extremely limited in its legitimacy and is never legitimate when taken from one private entity and given to another private entity.
There are legitimate uses for eminent domain but they are pretty rare these days. In the case of the new bridge over the Detroit river, average property values in the Delray neighborhood shot up from around $5 grand to over $30 grand practically overnight in anticipation of the land being taken.
Funny you should bring that up: that's the one where the government is using eminent domain for the express purpose of putting a private company, the Ambassador Bridge Co., out of business.
Is THAT a legitimate use?