As you may or may not know, iPhone UDIDs have been leaked out onto the internet and peopel are freaking out about this whole incident. While we now (thankfully) know that the UDIDs did not come off of a FBI laptop, that (honestly) does not make much of a difference.
The UDID on iOS devices isn't really a big deal. For developers it's just a way to provision apps to work on devices. Not much interesting here