I think the various version of that slide that were floating around were some of the most confusing bits of build. It's pretty obvious a few people tried to tweak the original to make it clearer, but all that accomplished was increasing confusion.

,CKurt wrote

Next, it is also unclear if Desktop Applications (WPF , SilverLight OOB, WinForms) will be able to use the new WinRT API's or should keep using the ugly COM way of tapping into Windows.

It's been stated that older style applications will not be able to call into WinRT and WinRT apps will only be able to use the approved subset of Win32 apis and COM objects (though that subset is not entirely defined yet)