An analysis on conntact.com covers the major issues thoroughly. Basically:
- Companies which have extended benefits to unmarried, non-civil-union partners have to revisit their programs and decide whether to require marriage or civil unions, thus stripping some existing benefits.
- Alternately, they can tee off many employees simultaneously by stopping spousal-type benefits for everyone. (Not gonna happen.)
- Instead, they can extend benefits to every form of spousal equivalent. (Makes sense, but will cost more for them.)
- They must be even handed, while recognizing civil unions as equal to marriage for benefits. Otherwise, they are discriminating by law.