xScape themes due to complexity of the framework can’t support child themes. This is the case with most themes that are framework based. But, there are several way to add your own styles without loosing the base theme due to some advanced features xScape framework has to offer.
New version of my jQuery plugin jGD DropDown is here and it brings several new features, bug fixes and more examples for plugin use. There are more interesting features planned for future versions (including checkboxes for elements), but I don’t have too much time to work on it.
I managed to make lightScape working, and the beta version is now on the xScape.info demo website. Theme is not yet completed, and in the next week more styles (15-16) will be added, styling for elements improved. So, test it and leave suggestions in comments or forum.