Hetero Civil Unions?

Dale Carpenter reads Illinois' new civil unions bill:

There are a couple of noteworthy provisions in the bill. First, the new status is available to opposite-sex spouses who choose not to marry. This makes the Illinois law different from other civil-union laws, like the ones in California, Oregon, and New Jersey, which generally make the equivalent status available only to same-sex couples on the theory that opposite-sex couples can marry. 

Which means to say it offers marriage-lite, undermining heterosexual marriage in a far more profound way than marriage equality ever would.