postupgrade?

[Tom Horsley]

I'm never likely to trust upgrading from one version of
fedora to the next. I like to do clean installs, giving me
a chance to start fresh, but I do (eventually) tend to
get all the stuff installed on the new fedora that I had
on the old fedora (which I keep around on a different
partition - another reason I like clean installs).

The last few releases I have been comparing the rpm -q -a
list in old and new to try and guess what I need to install
to get the equivalent stuff, but sometimes new programs
get substituted for old, and there are also all the
random things like themes and artwork which have different
sets installed by default and I don't usually want to drag
them along.

So, is there anything like a "postupgrade" tool that would
be sort of the inverse of "preupgrade" that can automate
picking the rpms I need to install to make a new fedora
install as much like an older one as possible? (substituting
new tools and artwork for old where appropriate)