Hi all !
I got my hands on the Canon SDK and wrote a little app for remote-capturing images. By now it has live-preview via USB, full resolution capturing, one level of onion-skinning and of course a possibility to review the already captured frames.
I'm going to add the following features: autofocus-lock (a shame manual focus isn't possible remotely), macro-mode-switch, multilevel-onion-skinning and playback at constant (selectable) framerate. It won't be an all-in-one solution, only for frame capturing (no sound or colour-keying or whatever, there are better tools for that)
Currently, I tested it with my A520, but nearly all Powershots should work.
Anyone interested ?
To get CSMC, look here... (free download)