You would have to be one hell of a contortionist to make the stretch that this is some sort of First Amendment issue. Whether or not the DMCA is a good law is still an entirely separate argument, but this is nowhere near a free speech issue.
What he did was release the key, which still happens to be Sony's private key (read: theirs), in order to bypass the security of this system. Fail0verflow, who actually found the key, did the (relatively) right thing and realized the screw-up and sat on it, which is why they're not in that much of legal trouble, Things would have been fine if that twit St. George wouldn't have done the internet equivalent of breaking out the bullhorn and yelling "Hey, I got my hands on the security key to the PS3, but don't use it for piracy *wink wink*" ... and THAT is why this case is where it is.
Yes, Sony has been a pretty big dick about things the last 5+ years(CD rootkit, general quality of their hardware, etc...), but speaking as a software dev, they do have the right to try to protect the works for their game studios/3rd parties who develop for their system. If they were let piracy run rampant on the machine, which face it, that's what most "homebrew" would have been for, PS3 gamers would only have to look forward to our yearly allotment of Madden/COD games.