This item is still under review by the feature team. I have no details as to when a decision might happen.
In addition to making it more obvious WHERE the activity is, how about improving the display so that past read conversations/items in the feed are collapsed or hidden UNLESS there is something new. My feed is full of stuff I've already seen -- other tools seem able to hide what you've already seen, allowing you to more easily spot the new stuff.
Agree with others about badges that are specific to different teams or conversations.