These are major blows against the tradition in US law of protecting DRM, even when DRM wasn't upholding copyright. For example, Apple argued in its Copyright Office filing that it should be illegal under copyright law to install iPhone software unless Apple had approved and supplied it (akin to the principle that you should only be allowed company-approved bread in your toaster, or Folgers-approved milk in your instant coffee).
I'm not clear on whether these rulings now make it legal to traffick in circumvention tools that can accomplish this trick: if so, it would mean that you could sell DRM-ripping software in stores, or open a fix-it shop that jailbroke iPhones so that they could access unapproved software from third-party suppliers (including online stores that competed with Apple's App Store).
In any event, major kudos to EFF for an enormous win. I've always maintained that the biggest problem with DRM is the special status the law affords it: prior to 1998's Digital Millennium Copyright Act, a company that wanted to control how you used your purchases had to devote serious, ongoing effort to stopping the companies that sprang up to undo their locks; consequently, the market was able to drive DRM into the dust quickly, as companies abandoned strategies that squandered profits to lock down products. But after DRM got special treatment under the law, companies could merely slap on the thinnest veneer of DRM (the iPad's DRM was broken in less than a day!) and count on a public subsidy to defend it, through the courts and the law.
This was pure moral hazard, an invitation to the world's corporate bullies to invent "business models" based on stopping you from fully enjoying your property unless you paid to "unlock" every feature and morsel of value latent in it. Like a fridge that you have feed quarters into if you want to chill anything except dairy products, or a shower that charges you extra to rinse off the dog. Companies could create these ridiculous businesses and count on the government to police them, externalizing the cost of their extraordinary chutzpah to the very customers they were inflicting it upon!
Ironicially, just as the US government is starting to reconsider this wisdom of this approach, other governments are being arm-twisted by the US trade representative into adopting it -- for example, Canada's pending Bill C32, a copyright law that was practically ghost-written by the American entertainment lobby and delivered after the Prime Minister's office handed down the edict to "Make the Americans happy."
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.