I guess it might be a huge number. I always wonder if there is a post on an interesting thread a month after I stopped checking the area. On other sites I click on View New Posts and then check out the ones that interest me. I then clear the new posts and start again. I’m just curious if it is available.
According to Tim Wilson, that option is not currently available. It seems to be a recurring request though. Hopefully, it will be implemented. I think that it would only encourage more participation, being able to easily see new posts and its subject line. If it were too overwhelming for some users, I guess they could simply not use the feature. There are quite a few features that we all don't use on a daily basis, but to some individuals these features are vital.