During this fall's elections, voters in twelve states considered anti-Kelo referendum initiatives that sought to ban or curtail the condemnation of private property in order to promote "economic development." Ten of the twelve passed, all by lopsided margins ranging from 55% to 86% of the vote. For a complete list, see here.
The only two anti-Kelo initiatives that failed were proposals in California and Idaho that were tied to complex and highly controversial "regulatory takings" proposals which would have required the government to compensate landowners whenever the value of their property is reduced by various types of government regulations; a stand-alone regulatory takings initiative was also defeated in the state of Washington. Tying anti-Kelo referenda to the much less popular regulatory takings referenda has turned out to be a serious political mistake.
More importantly, of the ten anti-Kelo initiatives that passed, at least six (Arizona, Florida, Louisiana, Nevada, North Dakota, and Oregon) and possibly seven (counting Michigan) are well enough worded to provide strong protection to property owners that would succeed in banning all or most economic development takings in those states. This is a much better batting average than that of post-Kelo reforms enacted by state legislatures, most of which tend to provide little or no protection for property owners (see, e.g., my analysis here, here, and here, and Tim Sandefur's excellent article on the subject).
Why are the anti-Kelo referendum initiatives so much more effective than most of their legislative cousins? I suspect because the former are usually drafted by property rights activists rather than by state legislators. As I discuss in more detail in the posts linked above, politicians often have incentives to give voters the impression that they are "reforming" eminent domain without actually doing so. Activist groups have few if any such incentives and the reforms they draft are therefore likely to have fewer loopholes and be more effective in eliminating economic development takings.
If time permits, I hope to produce a more detailed summary of the state of post-Kelo reform soon.