I have uploaded my personal button addon for the BC beta addon author community to see what I did in using the new secure templates. I defer expertise in lua to others, but I think I have a solid foundation for using state-driven buttons.
http://www.wowinterface.com/download...php?s=&id=5528
The bottom 12 buttons will change based on stance, will carry the key bindings you set in the default interface, and as a bonus druids get a unique 12-button bar for either moonkin or tree of life forms.
As I refine my code and functionality I will update this addon until one of the uber button authors gets their BC beta public.