There also seems to be a plugin called "Autosubscriber" in closed beta testing stage, so I guess we have to wait for that.
yes, you are right... please, wait some time... JComments and all it plugin developed by only one person, and I haven't so much time to made all things at one moment (I've got family, work and need some time to rest). The nearest plans about JComments are:
1. Release new version of JComments 2.1.x
2. Release JComments Top Posters module
3. Release JComments AutoSubscribe plugin
4. Release JComments ContentPlugins plugin (allows use content plugins in comments)