I've noticed that a lot of skins don't include the images for the firmware update screen (part of the plug-in) or the patch screen (companion folder to UI in _dstwo folder). I think the only skins I've seen to be this complete are those by VatoLoco, like "Don't Panic", "Green Neon", and "Tron". I commend VatoLoco for going the extra mile. In my opinion, it looks cheesy when I see "Pink" leftovers in the patch screen after using an awesome skin.
Now before this starts a flame war, I am not proficient enough with graphic apps to make my own backgrounds and icons. I'm just wondering how difficult it is to do a complete suite like "Don't Panic". I know that the user has to copy a lot of file to a lot of places (and hopefully be smart enough to backup the default files), but to me it's worth it to have a complete theme.