Elements work like they've always done, this just moves the commonly
used components away from the global namespace.
The qmldir file still does something, although at this point it is
unknown exactly how it's used and whether or not it could be changed to
simplify imports across the block.
The QML at the moment is a giant mess. Moving pages into individual
folders and properly abstracting the sub components of the pages will
allow for much easier development and better error messages.
Additionally it will prevent polluting the global namespace. Really, all
the reasons for avoiding globally available values and using
abstractions in regular programming also come into play here.
Vasily