I think the idea of having a way to keep track of new comments is good. It's a cool way to keep track of active discussions. It's also on the same line of thought as keeping track of new posts in a community, so the two can share an implementation base.
I'll definitely consider this when I get to work on these features.
Another factor that will need to considered is avoiding noise from this feature, by making the feature "optional." I mean, you won't get notified about replies to posts unless you check a button that says "Follow this conversation" to follow that particular post.
Thanks for the feedback, I've added it to my notes :)
Great, thanks!
About notifications, yes, certainly it makes sense for a notification about new comments to be shown under your Notifications only for posts that you explicitly follow. If notifications are shown for new comments on all posts that you have simply opened (but not followed), then the notifications become quite noisy.
For posts not explicitly followed: I think there would be a lot of posts (ongoing discussions) that a person is interested in. It won't be just a few. So it becomes a hassle and cumbersome to have to click "Follow this conversation" on every post I'm interested in. Much easier would be if I have a visual way of knowing how many comments are new since the last time I opened the post. Then it's not creating noise for me (this info is not in my notifications). I can decide whether I am still interested and whether I want to go inside the post and see the new comments.
So I guess that gives me more choice because there is two different levels of interest: posts that are explicitly followed and posts that are only opened. For the first, I get a notification under my Notifications. For the latter, I only get a simple visual indication of how many new comments there are since the last time I opened the post.
Or something along those lines. Let me know what you think. Maybe there are even better ways of handling this. Would be cool to get more perspective from more people before any work is started.