how to determain those no longer required packages

[Seth Vidal]

On Mon, 31 Aug 2009, James Antill wrote:

> ...you don't get rid of any extra stuff you got with blah, hopefully
> "yum history undo" will solve that in a better way by recording what
> happened at #1 and undoing it instead of trying to piece together what
> might have happened at #1 after the fact.
>
>

let's not go promising things like yum history undo which are not 
committed, not tested and, in the case of large update/install 
transactions, unlikely to do what the user wants.

-sv