Ex. The Game SIG could maintain an ini files with featured Game in Fedora, to make it easy for the users to install/remove these games.
See? Even in Fedora such thing have its place :) .
Also, packagers could create own ini [or other file, ini is so windowsish] file which would install all required packages and so others...
In openSUSE, Ubuntu and derivatives adding 3rd party is required, because they have old packages in repo, or some packages are missing in the repo, while Ubuntu is so happy, because it has big repo...
We can make a software portal (I can help, I can help :D !) with such files to make browsing repo easier (but if PackageKit implements icons there will be no difference).