When writing an addin that has a toolbar, I have to call a method that will create a toolbar for me, then add the the returned toolbar to my container. I think, since the toolbar is always on some edge of the container, and usually on the top edge, that SD itself can create a container with the wanted toolbar(s), leaving the addin programmer only to write the work-area and the commands.
This is of course a very small change for anyone who writes an addin, a matter of another line or two of code, but it could be a nicer way to do things.
Itai.