Well we already have a couple of IM apps so it wouldn't be of use to us but in general it sounds a cool idea. We were thinking of a twitter feed from the desk, anybody thought about this?
I believe if you have LDMS configured there is a Chat ability within the right click integration with Service Desk. I think that might only be dedicated for the owner of a machine you select but it might be a start for them to get this in place.
I could be wrong, but there should be some type of tie-in.