I think this is a really good idea. If the Unix philosophy of each program doing one task is taken to its logical conclusion then "applications" are just GUIs around something. For example, looking at Music Player Daemon (or even Gstreamer) frontends there is no point listing codec support and things, since they're all the same. The only difference is the GUI, which can be reasonably portrayed in a screenshot.
Plus the fact that having such a wide choice of programs means that names like "Ubuntu Media Player" don't make sense, thus we have Banshee, Rhythmbox, X MultiMedia System, Beep Media Player, Amarok, JuK, etc. which can be confusing, but being able to see the application beforehand makes finding one's favourite easier since the name doesn't need to be remembered.