Enhancing the upgrade/install experience

[Jim Bevier]

I need some help.....

During testing of different rawhide releases (alpha, beta, rc's, etc) I usually 
have an existing system and would like to install a "duplicate" of my old 
system.  This is also true if I upgrade from release to release.  I would like 
to get a list of existing packages (rpm -qa | sort > package_list) and somehow 
feed this into yum (or?) and have the packages installed if not already 
installed.  I would also need a list of packages that could not be installed. 
This way I could start with the live cd or install dvd, do a fresh install and 
then update to a duplicate of my old system.  So, is this functionality 
available?  Can it be?

Jim