It’s been talked about for a while now but it’s now available for iPhone and iPad. iPad owners in particular get excited as with this update you get multitasking, folders and all the other goodness from iOS4 on your iPad.
We’ve put together here links to the best reviews of the new version of iOS.
Praseela Feltenstein on 
[...] the new iOS 4.2 coming out yesterday for iPhone and iPad, there were some major new features. But one feature that did catch my attention that I didn’t think was going to happen [...]