Apparently it's been ruled legal in the US to jailbreak your iphone among other things.
As I don't have an iphone, the details here aren't all that relevant to me. It's nice that there's legal protection for cracking inoperative dongle DRM but most people in that position were probably doing it anyway, and the safedisc/securom stuff is for people doing security research and doesn't involve me afaik.
And ebooks are still locked up tightly enough that I'm not comfortable buying most of them. (I do buy ebooks, and I pay a lot more per-unit for them than I do for the stacks of used books I also buy, but I buy only from vendors who provide unlocked HTML copies. Yes, it's therefore piratable, but it means I can load it onto whatever display device I please, resize it, and generally benefit from it being electronic rather than paper. If I can't do that, I'd much rather get a physical book.)