I have no great observation or any data, only anecdotal and that is no good for anything here. At the same time I have seen plenty of things like this blow up and then turn to dust time after time and chasing them on forums gets to be a pain for no great gain. I do however know it has thus far failed to penetrate the business or in many cases general user markets and if it is just games then we have been here before with teamspeak, ventrillo, mumble and the list goes on.
Equally "I'm sure 5 years later" -- 5 years would be an amazing lifetime for a piece of software like this. Were it to be that then the hassles of adding it to the contact page and sorting it during forum upgrades and such like would probably be well worth it. The turnabout on these things is often in the 5 months range though.
I will agree that am probably overly cynical and that has resulted in me dismissing most such things for my personal use, to then stick with IRC and email (they are there, the are on everything, it takes a lot of extra layers but they still work however many decades on this is), and maybe missing out on a lot but ultimately feeling smug when it all goes down in flames or just becomes a skeleton factory.