3rd party packages etc after upgrade to hoary

[Sean Hammond]

When you upgrade from Warty to Hoary, what becomes of any 3rd party
packages and repositories you were using? Particularly, I upgraded by
just blanking my sources.list file and replacing it with a clean hoary
sources file (replacing all instances of warty with hoary didn't work,
I don't remember the exact erro). So what became of those packages?
Are they still installed? Is there a way to see them and remove them,
perhaps replacing them with hoary equivalents?

Currently I don't seem to have any 3rd party packages in synaptic,
except for some jrfronseca one, don't know where that came from.
Basically I'm starting to get confused about the package management
here.