It all gets back to them looking for crafty ways of compelling behavior they can't (yet) outright do by legislative or regulatory order. In this case, it's a large corporation prying into its employees' lives and functioning, essentially, as a proxy for the government. Basically what happens is that our rights might continue to exist on paper, but become increasingly meaningless in practice. Already you experience it any time you take a flight. Queue up for the genital groping, and no there's no violation of your 4th Amendment rights because you have "voluntarily" forfeit them by virtue of purchasing a ticket for a flight. You still have your 4th Amendment rights, and if it means that much to you then you can choose to not travel by air. Or train. Or, increasingly, on highways. See how it grows like a cancer? ObamaCare is the cherry on top for this governing philosophy of theirs, because they'll be able to compel you to do whatever they want while claiming they haven't infringed on any of your rights. After all, you don't have to do what they compel if you don't want to, you are free to not go to the doctor ever. But if you want to receive medical care, then as a condition of access you will "voluntarily" forfeit this right and that right.
It's virtually unlimited what they can do with this governing concept, and I have no doubt they plan to test just how unlimited it is.