Bringing a legal action like this just raises the public awareness to the hack (not good for Sony). It pisses more hackers off (not good for Sony) and it doesn't fix what seems to be an unfixable problem for Sony.
I'm sure the courts will be made aware that Sony removed a "key" feature/selling point of a console and left consumers with little choice about how to re-enable that feature.
Anyway, Geohot shouldn't have been such an egomaniac, the keys/tools could have been leaked online anonymously and he wouldn't be in legal trouble. Still, I can see an out of court settlement of some kind on the horizon...