I don't think Exalting can do this so follow along with me:
Example Scenario -
Big Rumors about Chaos Legions comes out. Hundreds of posts in response follow. One follow up post out of the 100 has an update to the rumor but gets completely lost in the masses, takes a half an hour to find or you subscribe to the post and get inundated with a whole lot of noise and no substance.
Sounds pretty typical and is in my opinion the biggest failing of large threads and forums in general.
Solution -
As above, except
News, Rumor or Major Update to the thread gets posted after 37 pages of drivel. Now the thread owner, a mod or power user can use the "major update" flag (Banna Wavva) for that post. Users that are subscribed to the thread or see the Banna Wavva flying on a thread know that something of consequence is going on and you need to read it. User clicks on the Wavva or on the subscription link that comes through and you are magically taken to the post that has been flagged.
I can see a ton of applications for use as a mod (not knowing what tools mods have already), also if I was a
DCM or higher and you could integrate your Dakka account to Twitter (hint hint

), then anytime you subscribed to a thread and the Banna Wavva for a post went up, you would get a tweet notification as an option as well. Also, now you could use the Banna Wavva as a search criteria thus cutting down on meaningless search results that have to be sifted through when all your doing is looking for the real meat and potatoes of a topic.
Okay enough rambling but I do know I would use this kind of feature and make Dakka preeminently useful when compared to other major forums.