This is a huge step in the right direction; however, it really doesn't change anything. People have been rooting devices for years, and it has always resulted in a 'voided' warranty. Voided if you are caught that is! The positive is that now the hypothetical concept of being prosecuted for doing so has been removed. Even if very few, if any, people actually ever were.
The part of all of this that I find the most intriguing is how devices that are exclusive to a particular carrier can now be legally 'unlocked' to be used with any carrier one so chooses. This sounds really cool, but when you break it down it really doesn't change much either....
Allow me to explain. Say you buy a device from Verizon that is an exclusive device to VZW. Now, you get that device unlocked so that you can use it on Sprint networks. Your Verizon warranty will be instantly voided. How do you now get a valid warranty, and with which carrier would it be with? Same with buying that same device from Best Buy or anywhere else for that matter. As soon as you unlock it, poof goes your warranty.
So, will we see big retailers like BB selling unlocked devices and then you get to choose your carrier? Oh that would be sweet, just like it is in Japan now from my understanding, but I bet the major carriers here won't go along willingly.
The other problem is what about the sweet upgrade discount that we all love? If you buy that exclusive VZW device and sign a new contract, you can't just cancel your contract and tell them "I'll just keep the device, thank you very much!" How many people really want to pay $500 bones for a device and then get to choose your carrier?
These developments are definitely great, but when it comes down to it, the carriers still have us by the balls I'm afraid.