Next to the subforum 'SFML projects' there's also the wiki on GitHub which stands free for anyone to use edit and contribute.
I think with those two options are quite enough. The forum is here for projects that are being worked on, so users can ask questions/make suggestions/say how awesome things are and if the projects are activily maintained they also will stay on the top and not get lost in the depth of the forum.
The wiki can more be used as some sort of summary and give an overview over diffrent projects, unfortunatly the
project section is quite empty, because not many are using it/know of it.
If you like to see some bigger list, then feel free to edit the wiki any time.
Although Laurent once wanted to update the website with the release of SFML 2, but seeing how busy he's with RL and the library itself I'm not sure if that is gonna happen, but if so maybe an better integration/linking to the wiki would be a nice feature.