Anyone, anyone, Bueller??
Hey Dan Bruhn - It doesn't look like there is any feature present today that will notify a series of users about discussions that do not have any replies. It would be worthwhile posting this as an idea to the Ideas for Jive place as a feature request with your use case - I expect other community members will vote this up. Our product managers use this area when planning out new features for future versions of the Jive platform.
Let me know if this helps.
Thanks for the response. I'll go ahead and create an idea for this.