Sen. Cornyn is introducing a federal bill (S. 1313, "The Protection of Homes, Small Businesses, and Private Property Act of 2005") that would bar "economic development" takings:

(a) . . . The power of eminent domain shall be available only for public use.

(b) . . . In this Act, the term "public use" shall not be construed to include economic development.

(c) . . . This act shall apply to (1) all exercises of eminent domain power by the Federal Government; and (2) all exercises of eminent domain power by State and local government through the use of Federal funds.

As I read this, the bill would only apply when states and local governments use federal funds to pay for the taken property (since that's the only time the "eminent domain power" is "exercise[d]" "through the use of Federal funds"); it wouldn't matter whether they use federal funds for the rest of the development project. I suspect that this means the effect on state and local takings will be modest, though perhaps the symbolic impact might be more substantial.

Here's Sen. Cornyn's floor statement and his press release.