Really useful walkthrough for those of us too busy to poke into the innards. Summary:

iOS 4.2 on iPad is a revelation. It’s the way iPad is meant to be. That’s not to say it’s perfect or has every feature on every geek’s wish list — it certainly doesn’t — but it has enough new functionality to make iPad much more valuable.

Like with iOS 4 on iPhone, multitasking and folders extend the existing UI in a way that gives power users what they need, but keeps casual users either grounded in familiar metaphor, and feature-phone types blissfully unaware it’s even there.

AirPrint addresses an important bit of functionality for home and business alike, and AirPlay has the potential to turn the TV video scene upside down.

Worth browsing in full. I learned a lot from it.