I've spent a bit of time looking into the theming aspects of Siemens phones, as I'm considering the S65 as my next choice. Anyway, after a lot of questioning the right people and experimenting instead of working - I've pretty much got the basics
As a test theme, I converted my metal theme I did for the T610/K700:

The icons on the desktop are from the CX65/M65 - S65 will have better ones.
There are several animated aspects to the theme, my example has nowt fancy, but each is as follows:
Startup

Shutdown

Network Search

Screensaver

Pin Input

Please Wait

The colour scheme supports full transparency - seemingly on everything. The colour file or skin as siemens call it contains 60 lines for 60 different sections of the skin.
Anyway, that's me for now - just incase anyone wondered where I was