The Small Wave.

First, Jailbreaking was never really illegal. If legality is what kept anyone from doing it I think they were misinformed. It was a gray area awaiting a ruling either way; Apple wanted the court to settle the question as to whether jailbreaking violated copyright, and they did, though not in Apple's way.

There is zero evidence to support Apple would have gone after individual jailbreakers (had the ruling gone the other way), any more than they go after one-off Hackintoshers. 

I believe Apple wanted the shield of illegality not to go after geeks, hobbyists, etc., but rather to stop the unscrupulous who may now crawl out of the woodwork to make a quick buck on this. 

I can practically see "Jailbreak Kits" for sale already. Their marketing copy gushing about how this once forbidden activity is now available to the general public. They'll publish a link to the Library of Congress statement that few will read and fewer will understand. They sure as heck won't dwell on the practice being unsupported, or that the next iOS release will likely kill it. Money in hand, they're off to the next sucker leaving their current "customers" yelling at Apple as if it's Apple's fault. 

Finally, Apple will continue to "break" jailbreaks. Not only does the statement not mean Apple must allow the activity, but I believe every jailbreak so far relies on a security exploit. Of course Apple's going to plug that hole. They better. 

[UPDATE:] See this excellent post for more information what today's copyright ruling really says.