And that is the exact danger of allowing "projections" to stand as justification. All the government has to do is say "I think that we might possibly get more money if we take so-and-so's property;" arguably Kelo v. New London was the Suprem Court's repudiation of property-rights in whole.
I couldn’t agree with you more; the start of the slippery slope was when rather than using eminent domain for projects that truly served the public “good” (lengthening airport runways, widening roadways, etc.), it was being used for private developers’ moneymaking schemes (whether for housing developments or corporate uses). I remember a few years ago in Neptune, NJ, people put up a stink because they were being forced out of their homes so a developer could build other housing that the current residents could never afford; it was gentrification-via-eminent-domain. I don’t know if the project ever got off the ground.