Ste,
Yes, it is possible with what currently exists.
I got tired of trying to promote the single html file version of TWederation because it has been around for about 3 years and with 4 or 5 very notable exceptions there was almost no response past 'I would like to try it when it is ready' despite it being ready.
After that I just didn't care enough to try and publicise it.
I am currently working on making inter-server federation work on Bob so that you can selectively sync with remote servers and have a mesh of servers working as a forum/IM system.
And on top of that I am playing with the components needed so that you could run it on your computer/phone/whatever and it could hook into the mesh as long as you could contact at least one other node on it. Or you could just run your own local or publicly available mesh.
In short, yes I am interested and this is a big reason that the next version of Bob is taking so long.
OokTech is probably going to start offering hosting for wikis on a Bob server in the near future (shh, it's a secret)