Is there any evidence that any site anywhere has seen an uptick in comment quality by requiring real names?
Anecdotally, any time I see a news website with Facebook Connect the comments are still swill. While I'd be willing to consider evidence to the contrary, I think this is a false correlation. Observing that anonymous comment threads tend to have more swill than social network threads says nothing. People act more like they would in real life on Facebook because Facebook has always tried to tie your online identity with your meatspace identity. Slapping real names on YouTube accounts makes them easier to stalk, and possibly easier to humiliate outside of the site, but it doesn't stop them from being a conglomerate of barely-literate human beings who are strangers to almost everybody and will rarely interact with each other more than once.