meanwhile MediaBox home widget for Diablo is in extras-devel. testing is highly appreciated.
known issues:
1. Widget fails to start at hildon-desktop start after reboot (if anyone could test it in SDK and attach the log it will be wonderful), but after selecting it again in home menu it appears on the screen.
2. CPU consumption is not enough optimized.
3. Seek doesn't work for some reason (a bug in MediaBox?)
4. No cover art support at the moment.

video playback on n810 is horrible, 'cause video is not scaled proportionally, it just fills a constant rectangle.