I worry about internal social media burning itself out a bit too. It can be a great tool used judiciously but almost too much excitement about it and then getting tired of it. Right now I notice lots of activity on LinkedIn as people jump on board this platform.
This reminds me of blog comments about 7 years ago and some of the other tools from a few years ago that have faded away. Once all the hype dies down perhaps we will integrate social media as a vital community and collaboration tool. Having said that some are doing it well and some are just dismissive without looking at what is going on.