The DOJ has already sued and will likely win as Constitutionally interstate trade/commerce is regulated by the Federal Gov. This will obviously play out in the courts, and likely pretty quick... CA is nearly bankrupt and the Federal is leaking cash like crazy so we will see who's team of lawyers will win in the end.
Meanwhile, as a webmaster, we can't have two sets of rules. ONE will have to prevail.
You'll understand what this really is if your read the law.
California residents overwhelming pushed for this the last year, pressuring our state legislature. This will stop the throttling that out-of-state ISPs impose on stream services used by California residents.
Meanwhile, as a webmaster, my site won't be slowed down to users in California that use out-of-state ISPs.