I uploaded a pre release at
http://www.jidesoft.com/evaluation/arch ... e.eval.zip. The two methods are added are protected methods - createGadgetButtonContainer and recreateGadgetButtons. You can refer to javadoc to see how to override these two methods to do what you needed. BTW, in order to subclass GadgetPalette, you need to override createGadgetPalette of SingleDashboardHolder, DashboardTabbedPane or DashbordDocumentPane depending on which dashboard implementation you are using.
The reason we can't do this in our core code is because we don't have a category concept for the gadgets. However you can subclass Gadget to create CategorizedGadget for example which has a new property called category. Then based on this category property, you can override these two methods to put different gadget buttons to different tabs.
Thanks,