I love the idea. Such kind of “Dashboard” would definitely enhanced the network stickiness of all users and can make it easier for them to “follow” their latest activities or in case of “inactivity” to inspire them to contribute “something”, e.g. “join the conversation”.
To my opinion such a dashboard should be flexibel for each user. Starting with a set of standard content/data aggregation (simple: “Forum threads I created”, “Forum threads …”) maybe 5 X. For User with more and/or other interests in X, they can flexibel create their dashboard to a maximum, of maybe 10 X.
For example, my interests are in the field of X`s which belong in the space of Group-Activity. What is happening in the Groups which i am following? Track the Group.
Because of my plans for a new web project. I would donate or spend some amount for developing such a plugin.
(By the way I am looking/hiring for buddypress web/plugin dev’s (freelance) – pm me)