What you seem to fail to grasp is that the internet does not magically appear on the vpn side it still fetches the data and those ISPs will be bound by the same laws that govern the rest, they'll just have to subpeona them before they find you.
What you fail to realize is that this isn't a law. It's a strong arm tactic coming from Hollywood because they couldn't get the law they wanted passed. It amounts to nothing more than a deal made in a smoker room that has no real legal authority.
In order for the ISP to subpoena you're records from the VPN, the law must get involved. That means one of three things.
1. Your ISP has contacted local/regional/national law enforcement and those authorities have engaged in a criminal investigation. This is unlikely, seeing as it took them more than 2 years to move on MegaUpload after they started the investigation. For even the most blatant "pirates" law enforcement is generally going to laugh your ISP out of the room when they request this, unless they have reason to believe you're into some pedo shit.
2. The same as above, but the copyright holder is the one requesting the investigation as opposed to your ISP. Again, for the most part law enforcement is going to laugh them out of the room. Even though it may not seem like it at times, they do have more pressing matters than making sure you aren't downloading something you failed to purchase.
3. Either your ISP or the copyright holder has initiated a civil suit against you. At this point they can then attempt to subpena these records from your VPN provider. However, your ISP is unlikely to do this for a variety of reasons. The primary reason being the costs involved for them. At that point they're doing nothing but wasting their money by both losing customers and incurring legal costs. If the Hollywood side of things attempts this route, your odds of getting caught are no higher after July 12 than they are now. Additionally, if they flood the court systems with this, eventually copyright laws will be changed in order to relieve the burden these types of civil suits place on the court dockets. The MPAA and RIAA do not want that because any change in the copyright laws to relieve a burden on the system would result in a loosening of copyright restrictions.
Ultimately, the most likely thing to happen in any of these events when it comes to a VPN being involved is your ISP cutting off service. At which point you'd be free to move to another service provider.
If ISPs decided to create a blacklist, like so many tinfoil hat folk think, this would be shut down in short order. Unless denial to internet access were ordered by a legal authority (which would mean them taking your ass to court one way or another), a blacklist would ultimately end in litigation charging the ISPs with one form or another of collusion. Pretty sure that's a mess they aren't going to want to deal with because it would ultimately end in a costly class action suit. It would be nearly impossible for the ISPs to show that each member of the class action suit was guilty of malicious and continued illegal usage of the internet, but it would be rather easy for the class actioners to show they had been discriminated against and blacklisted for unfounded reasons by a group of ISPs acting in collusion to deny service. This would likely be especially easy with a jury trial given the overwhelming opposition of the public to things like SOPA and PIPA.
The Internet isn't dead. It isn't dying. And it's unlikely to be any less "free" than it is right now until (at least in the U.S.) until the government decides to go the route of China and completely ban access to sites at the national level. This shit is just another bump in the road that people will have to travel over. They'll make an example of a few people and then 12 months later no one will give a shit again. Just like with Napster and so many other dog and pony shows.