As for the actual concept & idea, that would be great!
But just in the way of execution of it,& how things are mentioned, I can't help thinking that some of the legwork could be saved.
As has already been mentioned a lot of the projects mentioned have Mods/people already heavily involved here at EAB,(or Emu UK). Rather than having to devote extra time/energy to a dedicated site, it'd make more sense to maintain the "group collectives" through sites here & at Emu UK?
Perhaps to make it easier for those groups to communicate amongst one another though they should have a dedicated area of EAB/Emu UK they can can exclusively communicate with each other (As in strictly for that group & not for normal members, like a Mods only type area),& when happy to make announcements/post ideas for feedback on will have a ready-made forum/feedback area to talk to.
(And of course their own official sites)
And I don't mean that in an ego-style thing,I would just think it makes sense to use the most useful available "tools" to hand & which would allow said groups to concentrate their energy on the tasks (be it CAPS,HOL,WHD etc), at hand, & minimize overheads.