Why were these classes renamed and can we revert this?

[micschk]

The classnames used to be so simple that even I understood what one did what :-)
We basically had 'Inputs' and one unified MediaUpdate (e.g. a post):

For some reason these classes have been renamed (sans comments/explanations) and now I find myself trying to figure out what class does what over and over... Apparently we now have 'Resource', 'Stream'(?), and different types of 'Media'? To me these new names are ambiguous if not plain off...