My two favorite new features of the new DK4 has to be the new reputation engine and groups.... have been really impressed with how well they both were thought through ahead of time, and also about how much once the "real world" implementation has hit, how they are doing so far.
I think the Trusted User status and Mojo is fascinating to watch... and i think the addition of a true reputation engine into the DK4 platform was long needed and innovative... and the linkage of "Mojo" to TU status, as well as the linkage of TU status to recommending comments, Group creation, editing meta tags etc.... All well planned and impressive.
Like anything it will shift and change and morph as real humans interact with it. And folks will abuse and game the system and then it will shift and morph some more.
But in a space where political technologies often are just an echo of what was cool elsewhere two years ago, this does feel like true innovation and progress.
And no easy trick. A good interview talking over the challenges at attempts at "trust engines" or reputation engines is here...
And I've been thinking a lot about other systems like Wikipedia, Ebay, Amazon, or even how Whuffie Bank for Twitter - as each system attempts to handle reputation systems, community, and real human beings.
And I'm still exploring. So anyone who has good links to diaries digging deeper into the specifics of TU/Mojo/Reputation on DK4, do post it in comments or send me a message.