I'm not 100% clear on what you are asking about. Are you talking about a hard drive based media server?
If so, some reasons why there isn't a whole lot of talk about genuine HD content on hard drive media servers is cost, size and lack of content.
Quite a few people use hard drive media servers for their music and/or DVD collections. But for HD content, the amount of disc space required goes up exponentially. If I want to have a media server with all of my Blu-ray movies on it, I'd need some 6 TB of hard drive disc space just for the Blu-ray movies alone! It just isn't terribly practical or affordable yet and it makes more sense to just use a Blu-ray player and the discs themselves for the time being.
Getting HD content in other ways is still less than satisfactory. Getting HD content off of a Cable or Satellite HD-DVR and onto the media server requires fairly expensive mods, since it is not a legally supported feature right out of the box. And while over-the-air recording certainly works, not everyone is using over-the-air for their HD television receptions. Case in point, up here in Canada, over-the-air is barely used by anyone since we receive so few channels that way up here.
Finally, there is downloadable HD content. For some services, the problem is once again getting it off of the proprietary hardware and onto the hard drive server. In other cases, it's just a matter of the quality not being there yet to make the effort worth while. Quite frankly, I have no use for barely better than DVD quality in the form of highly compressed 720p feeds with 2-channel audio or highly compressed Dolby Digital. That isn't HD. It's DVD+.
