Perhaps, (Just an idea,) say if I use @Simon in a thread, there is some form of notification to @Simon that he has been mentioned. This would just be something nice, so that if I ask someone a question, and they answer it outside of convo, I'll know pretty fast. Besides, maybe more people will start actually saying who they are talking to, leading to less confusion.

Sort of how on Facebook, when I mention a friend's name, it tells them. This could also be optional, so anyone that finds them annoying could just turn them off.