For you dev (and adventurous) types out there, Sony Ericsson has released the software development kit for the still-unreleased Xperia X1.

What's in store?

Developers can use the Windows Mobile SDK, free of charge, to produce a wide variety of panels to meet the consumer’s demand for a rich, individualized multimedia experience on their phone. Users of the Xperia™ X1 will be spoilt for choice as they personalize their handset with panel applications to suit their mood and lifestyle.   Whether it is a search engine, advanced calendar or social networking application, music or film catalogue, sports or news related content, the panels enable you to access any information – quickly and directly – with a simple tap on the 3” super high resolution touch screen.

So while you still can't get your hands on the phone, you can get a head start on customizing it.

Read the full press release here; get the SDK here; and check out a video with Ramanth Bhat, senior manager of application and product planning, speaking about the sliding panels interface, after the jump.