... I have to say that I really like how the notification drop-down is designed. Grouping the notifications by thread makes all the notifications much shorter, and the whole drop-down is easier to read than those I've seen in most other forum scripts. The use of bold text (mentioned by Fastidious) really helps the legibility, so it doesn't bother me much. But if it's hard to distinguish whether notifications are read or unread, perhaps some sort of tweak would be helpful.
... Unfortunately I haven't got any "unread" notifications at the moment, and haven't paid too much attention to them in the past, so I have to ask: What exactly is done to identify "unread" notifications as such? ... If someone could respond to this post (or even just like it) that would answer my question.