Sharepoint Wiki layering pages

As you can see in the official Powerpoint Power slides here: http://www.microsoft.com/germany/msdn/launch2008/library.aspx?id=SP_T16_DI_1800 a hierarchical view of sharepoint wiki pages can be programmed.

I searched the web and I just found blogs full of the known flaws of the SP wiki like: no comments, no images, no language markup, no full text search, etc.

but this is something that should be possible somehow, I hope.