I have read and/or am a member of all of those
Video Help is targeted at the hobbyist and is mainly support for software and file formats.
AfterDawn is similar, targeted at the hacking culture and the hobbyist for how to get things working.
Doom9 is targeted at "DVD backup resource(s)" and while more general than the above two, it has a similar target.
Video Production Support is targeted at the professional and prosumer (and maybe even the consumer) markets for helping with production as a primary focus, not the software/hardware used for it (although it will help with that).
MediaCollege is the closest to what I am doing by far, but the community there is mainly users of Dave's MC media player and not a general community.
I know that I need more content, the problem I have is that I do not want to make all the content myself and discourage visitors from submitting their own. I have begun an IRC channel for the website and hope to embed a java client on the page soon, hopefully this will get more visitors, but ideally the forums is where "it will all happen"
I suppose if even with me explaining it in a forum such as this that some people are not seeing exactly what I plan to do that maybe I should put a more in depth description of what I plan on the site.