A couple of points:
1. If this law is meant to protect religious beliefs only, then it will not protect Jewish bakers who get cake requests from Nazis, or homosexual photographers who get requests for services from WBC. (I'm not saying whether or not it's right or wrong; I'm just saying whether or not it's covered by the new law.) Nazis and WBC may be offensive but they aren't part of any religion's doctrinal prohibition.
An exception might be if the Nazi's cake request included wording on it such as, "Kill all the Jews" or if the WBC request was to photograph their members screaming, "Kill all fags." Then, the refusal of service would be because of the specific service request, NOT because of who was making the request.
2. In the previous cited cases of refusing service to customers, they weren't based on the business refusing to serve the customer as an individual but refusing to perform a specific service. Here's the difference:
Suppose a gay couple requests the baker to make a birthday cake for one of them. The baker says yes, because it's a birthday cake. The baker's religion has no doctrine against gay people celebrating birthdays. If the baker said no in this case, that would be discrimination against the customer, and the baker would NOT be protected by the new law.
Suppose that a customer ordered a ham and cheese sandwich at a Kosher Jewish deli. The deli owner could refuse to serve that food legally because the deli doesn't provide that service to anyone. That means, no customer, Gentile or Jew, will be served a ham and cheese sandwich. There's nothing discriminatory about that.
However, if a Jewish customer ordered a menu item at an Aryan-run restaurant, and was refused service because he was a Jew, then that would be discrimination because he was refused service simply because he was Jewish, not because of what he requested.