You are correct. I see a container in the ‘Site Summary Panel’ next to the slider with 4 tabs (Latest, Popular, Comments and Tags). I looked closer and it is indeed not a tabbedWidget, but another form of slider.
However, I still would love to have such a container as a widget in the sidebar of the graphene theme (No sliding). Can you put this on your wish list for future implementation? It would help to tidy-up the sidebar. Thanks,