Besides mouse gestures I've gotten so used to browsing via keyboard (especially when using Shift+arrow keys) that switching to another browser is nigh impossible, because I get irritated too easily.
And the builtin RSS reader is better than anything else I've come across (not that I spent that much time looking ;-))
"...most mobile PC makers did not think to themselves "how on earth are we going to go up against this""
What I've been hoping ever since yesterday is that someone should release an "iPad" with a heavily customized open source OS on it. Add some Amazon integration (ala iTunes for books/music), customize the main apps to suite the form factor and a semi-open repository/app store for extra apps.
I'm currently working on a mp3tag-like tag editor for Linux called puddletag which you can find at puddletag.sourceforge.net. Don't download it yet though. I'm releasing a update tomorrow with a large number of bugfixes and improvements.