Conversation threading and a unified inbox for multiple accounts are nice, provided you aren't using an alternate e-mail program such as Gmail's Web app. Even if you don't regularly touch the iPad's Mail app, iOS 4.2 adds one killer feature in the ability to open attachments in third-party apps. I was delighted to see that office documents can already be opened in for editing or saving to Google Docs.

Down: Game Center

I haven't spent much time yet with Game Center, Apple's gaming hub, but at first glance I can already see that it's . The app fails to automatically check for Game Center games you already own. You can't send messages or compare achievements. The ability to invite friends to a game is cool, but there's no easy to way to see which of your friends have the same game. Without these features, Game Center just feels like a thinly-veiled attempt to sell you more apps.