I hate to bring up the EULA thing since you had some very good points about it in your text wall

but I think that is where the lawyers will go.
I think the burden of proof in this case will be about intent. If Sony did not intend this to happen then it may well fall under their EULA statutes to change their system/service at any time for any reason. If the prosecuting parties can however bring burden of proof that this was intended, as you were saying for the aspect of making more money, rather then a "legitimate response" to the security hole etc. then I think they'll have a chance. The problem is legally speaking a "legitimate response" doesn't have to be the best one. I agree that Sony could have patched that breach, but why would they when they can do this and get more cash.
The problem with your false advertising argument is that it needs to be fraud for it to be false advertising. If Sony is simply doing their part to fix a problem within the infrastructure that they did not anticipate, it's not false advertising. It's like a product recall of anything that is defective.
In other words in the old days they would have simply recalled the units with Linux and replaced them with new PS3's without that as an option. However in the digital age they don't have to do that to make good, they simply need people to uninstall Linux and stick with Sony's OS. That's not against the law.
I understand your point, I just think that legally speaking that angle won't fly. The burden of proof must belie the intent of Sony to defraud thereby making their advertising false rather then just unfortunate due to the security issues they were having.
Unless they can link the hackers to Sony...

which I wouldn't put past the corporate world of cloak and dagger to do. They knew they were losing money, so they hired someone to attack the Linux side in order that they could have a good legal excuse for taking actions that would "safe guard the public" and net them significantly increased revenue. Of course proving that would be nigh impossible. I probably just sound like a conspiracy theorist.
