Seems to be a one hit wonder that never really had much going for it, the idea of getting mining power to do something useful is a good one, just xpm's got nothing much else.
What support I had for Primecoin is now behind Riecoin. If nothing more for the fact that Riecoin actually has a webpage with real organized information about it. It's pretty new, so not a lot of pools or exchanges support it yet. It's getting closer to breaking records, so I expect it will start to get some notice then.