HSSE comes with all editions of Cubase, so Steinberg already have an almost “free” player in the form of Cubase LE, and if there was a community-contributed free library for HSSE it would be a huge incentive for people to try out Cubase, and consequently HSSE and H5.
I’ve pointed this out before, but I think it would be great if you could create .vstsound files using H5 that were playable in HALion Sonic SE. It would be the opposite to Native Instruments … with them you get a free player, but have to pay for the libraries, and if you get a free library, it will only play in the full version of Kontakt.