I'd say that the proper libertarian solution is not to eliminate those benefits, but to detach them from marriage. Handle inheritance, hospital visitation, benefits sharing, and other such things directly, instead of linked to marriage. I think it would solve what the gay marriage proponents say they want, and probably a lot of other edge cases too. Who knows how many other people out there the current options aren't working for, but will never have the level of support gay marriage does to write new laws for their case?

But then, this was never really about benefits in the first place. If it was, they could have had civil unions a decade ago. This is about getting the Government to endorse it as Marriage to stuff it in the face of all the homophobes out there. This has always been entirely about ideological "BS", but not the kind the myself and any other libertarians are spewing.