Calm down, you're not losing any collective bargaining rights. Graduate assistants are not public employees, nor have public employees lost the ability to express collective will through unions. The only thing that the new legislation does is prevent public employee unions from legally forcing negotiations with government officials to occur. Unions organized around private industry never had this "right" to begin with, as their power comes from their collective will and striking capabilities, as opposed to power to force negotiations through law.
At the University of Wisconsin-Madison chemistry department graduate weekend, they told us exactly how this legislation will affect us. The university will be partially privatizing, resulting in higher tuition for the undergrads, but giving graduate students higher stipends and more representation in the administrative process. The graduate students still have access to the same health benefits as the faculty, which is not changing.
So, you can feel bad for the undergrads if you'd like, but as a graduate student, you're only going to benefit from this.