I've been crawling this thread since shortly after December when I got my SWR10 for Christmas. I've been agonizing over the fact that I can't find an API to tinker around with and really enjoy the tasker hacks and other ideas I found here. It kept bugging me that handyGames was able to integrate Aces of the Luftwaffe with the SWR10 though, so I continued digging.
It recently dawned on me that their game installs an extension for the SWR10 that can be selected in the Application Configuration. That's how the band is able to launch and interface with the game. Taking that tack I went and found this:
It's the API for creating extensions for Sony's smart devices.
I think it may be as simple as using com.sonyericsson.extras.liveware.extension.util.re gistration.RegistrationHelper to register your custom extension with the SmartBand application. After that, there are packages for interfacing with controls, notifications, and sensors. I'm going to play around with it, but my Java is pretty weak and I have two small children.
Thought I would post it here to get shot down quick, or drum up interest from someone with serious kung fu.