Now this is something I am sort of looking into already.
The problem I have is that we have yet to get our IT department on board to allow permissions for all sorts of things that are basically part of modern life and certainly part of libraries 2.0.
This is not a prority for them at the moment and we are stuck until they can come to our aid in accessing them.
This type of sharing would in fact be very useful for my workplace as the library service staff are spread over several sites and some bob about from site to site as well. I can see that there is a potential for developing data and passing on information as well as collaborating on specific projects with people in another building.
Ho hum that is a big what if so far on this one.
As far as Wikis go, I see that as the same as the social media options, ie not really for me.