Yeah its possible
and Yeah, its so easy you'll laugh your donkey off.

Simply save your background as a normal .bmp, rename it 01-12.bmp, and put it in /vsh/resource. Then go to Theme settings and select the top theme and voila you have a nice full res background with waves on top of it.

There are 2 known side effects:

1) You can only have one theme now.
2) The panels like the themes settings or when you click triangle in the Photo's menu, which are usually the color of the theme, are now grey.

But I can live with that...