The library that ships with Revit 9 was renamed and reorganised into the following structure:
Annotations > tags, symbols, etc
Components > 3D families
Detail Components > 2D families
Profiles > yeah, you guessed
Rendering > replacement cities file and default sky
Sample Files > samples of railings, stairs, roofs, etc

Unfortunately, it appears that after the library was completed and submitted for inclusion with the Revit 9 release, some families were added. These families were not renamed to match the new methodology, nor were they stored using the new filing convention. As a result the library is now neither this nor that....
Sigh....
We are aiming to get this replaced with a reorganised library in an upcoming build. In the meantime, we are also planning to include the Metric library on our content CD (due in July), reset to what was originally intended. Likewise the defaultAUSENU template is not, in fact, the final version that was supposed to be released.
Also, the renaming of the file was to remove the 'AUS_' appelation from the naming system. If there is no origin listed against the name (at the end) then it is suitable for use here. If there is an origin listed it is probably still suited (which is why it is included), but has not been rechecked for this release. In fact, over 600 new families have been added to the install, so there is a LOT of new material there to play with (the vast majority of it in Detail Components).
I will post here when a build is released with the 'corrected' metric library.
Regards,
Wes