Jeff Reifman, along with a small crew of volunteers and under-paid interns, recently launched CommonTimes.org. Capsule summary? CiteULike focused on news. Needs more mass but looks like it could be worth keeping an eye on. One neat little bit is the source stats breakdown in the left rail.
Interestingly, other than overall launch tone, I don't see anything that enforces so called "news" posting. Not that I'm advocating any such mechanisms, but an interesting study would be to look at a couple of tagging systems and see how much "topic drift" or abuse they receive. Define topic drift amongst yourselves.
The tagging concept is pretty much old hat. The big win so far has been in enabling social navigation. Next up, who can start to build really interesting analysis services on top of tagged content.