Beyond the iPhone [jailbreaking], the new DCMA exemptions allow academics to legally break DVD copy-protection to use films clips in the classroom, users to remove software and hardware security measures that are no longer supported by the publisher or manufacturer, and legalizes the investigation and correction of software flaws by third-parties.
This may be a very good thing. You can now – hopefully – legally use the electronic devices (iPhone, cell phone) and software that you purchased how you want. Of course, it is still highly restrictive and you cannot do a full scale duplication of something and give it away for free in the streets… but it is a start at least. Can you see any downsides?