I have been playing with Newsvine tonight. It is pretty slick.
I have often thought that you could run a digg style site for more general news. We will see how it goes. It will obviously live or die on the standard of community it can attract.
Some parts of it work really well. I like the little Ajax feature of telling you if your chosen username is available as you type, rather than after you submit the form.
Some parts of it could be better. The biggest letdown for me is that the article comments are not threaded. Digg and Slashdot seem to attract fairly similar types of readers, but while the best of slashdot comments can be really insightful and better than the articles, digg comments are nearly always 2 line wastes of pixels. If you only let people comment on the main story, you do not get the same degree of interaction as if you let them reply to previous comments.
I am also not sure if it is trying to be a US only site, or a world site, but US News and World News seem odd looked at from outside the US. The region dropdown lists cities in a few countries, so maybe they are confused about which readers they are aiming at.