I find it an interesting social phenomenon that the finite nature of content on the Web is lamented, when content has been temporal for all of human history.
I think that the medium, be it a hosting site or you own domain, will fail. What we need is maybe : a naming scheme that can transfer to different people (replicated files on different servers indexed by content hash? Aka anonymous ftp mirrors ... ) and common media ie readable by anyone, gracefully degrading.