The Left 4 Dead 1 and 2 beta communities are surprisingly active. There's a whole lot of beta recreation content for both Left 4 Dead games. Fortunately, we've also got access to tons of unused assets. I'd say most notably are the Terror-Strike era survivor player models and a whole bunch of cut models and textures from the unfinished "Dam It!" campaign. I think it'd be nice to have some of that stuff downloadable on the site just for easy access and for archiving purposes.