Just as we (most of us) are getting us to iOS 4.1 on our iPhones, Apple is letting loose the beta version of iOS 4.2 for development team members.
From some of the latest reading out there it sounds like many people are having trouble loading it though. I've heard about some people having new issues that they hadn't experienced before.
I guess that's why it's called a BETA version. Stand-by for more info.