We know what you're thinking -- it's Windows Mobile 6.1 fool, we've got the developers kit already. True, but not the SDK that allows developers to create custom, interactive panels for the touchscreen QWERTY's Panel Interface. Sony Ericsson claims that, "The Xperia X1 will offer the richest mobile user experience, putting the world at the fingertips of the user." In other words, the expectations have been set, developers, so you'd best get to downloading the free SDK -- you've got your work cut out for you. Sony Ericsson will offer a panel download service in the future, showcasing all the panels built by you, Google, and other partners.
The Panel Applications are meant to be simple, rich, and fully-interactive allowing quick access to your data -- eMail, calendar, multimedia, games, IM... you name it. But don't take our word for it, SE explains the new panel ecosystem in the video posted after the break.
Update: Screenshot of the rudimentary, "Get More Panels" interface after the break.