I think most of this is b/c all of the pkgs are being handed through to the apt and yum modules as one big line. This is to help speed up multiple package calls - which is extremely common.
If you'd like to return a list of which items were acted on and you settle on what kind of return values you want, let me know for the yum module - last time I checked i'm actually tracking the set of changed items but not specifically returning them.
-sv