OK, let me be more specific. I'm interested in how users find and organize theme, backgrounds, audio sets, icon sets, etc. and not so much in actual desktop or theme effects.

So, as an example, if you were to add a bunch of background sets from n900wallpapers.com eventually that little 5-line background selector is going to get a bit crowded. Personally, I think we could make things a bit easier by using tags or defining categories to make it easy to browse through the available selections.