how to determain those no longer required packages

[Ville Skyttä]

On Saturday 29 August 2009, Muayyad AlSadi wrote:
> warning: leaves in package-cleanup or remove-with-leaves could be your
> preferred application because it's a leaf [ie. no installed package
> depends on it, eg. pidgin or uget]

FWIW, there's also a show-leaves plugin which just lists installed packages 
that became leaves after a transaction.  Compared to remove-with-leaves, it 
doesn't remove anything, and lists new leaf packages also after install/update 
transactions in addition to erase ones.