It includes an an all-new, iPad-friendly user interface for Pages, Numbers, and Keynote, with popup galleries. Numbers also has a distinct, virtual numeric keypad.
It makes sense they have iWork, they're going to want some Office compatibility and light productivity to make the case for why you'd want an iPad instead of a netbook but... TiPb still wonders how easy it will be to input significant content via the iPad. We're willing to be convinced, we're jut not there yet.
Update: Turns out you can use a dock-based or Bluetooth Apple Keyboard with it!