In an earlier post I wrote about the book Remediation, in which David Jay Bolter and Richard Grusin argue that all successful media (all of which at some point have all been 'new') have started by repackaging existing content that was made for older media; i.e., they start as humble 'delivery mechanisms' for content which they don't question, and only later do new forms emerge. Recent conversations with colleagues have made me think of this again.
You could say that at the beginning, new media are secondary media. They not only 'refer' to a previous medium, but they offer a compromise: an experience that is not quite what the original medium provides, in exchange for increased convenience. Thus video, for example, offered a new way to experience movies, but without the big screen and ritual of the full cinema experience. Not quite the same, but good enough (in Clayton Christensen's sense) to be an accepctable alternative in some contexts, and good enough to eventually cannibalise the original practice itself. By this time, of course, the new medium is no longer secondary: it stops offering a poorer version of the original experience, and starts offering a primary experience in its own right--one which is desirable for its own sake, and one which the old medium can't offer. Crucial to this new content--content made for the new medium.
So what's the parallel in the case of Internet TV? Two things: the first is original video content, such as Yahoo's Kevin Sites experiment. The second--and more interesting one--is clips: short bitesized chunks of content aggregated in innovative interactive ways with playlists and video 'players' (like Motherload, Turbonick, the various Brightcove sites, or news 'players' like CNN's, or MSN's). The resulting aggregates are a genuinely new medium, one where TV and video--with their linear, self-contained nature--can't follow.
Despite all the new products, it is still early days. The real development will happen when these products migrate to the TV screen and the remote control--and there it is less that early days.
Still, the web is the laboratory where the new medium will be born.