The center column of pages like Latest Discussions, Greatest Discussions, and Latest Videos is the "main content" whereas the right column is essentially "bonus content" for non-mobile users -- bear in mind that if you're viewing DU on a mobile device, you don't get a right-column at all. So considering that the center column is the "meat" of those pages -- and because the page layout is wider on DU4 than it is on DU3 -- ultimately I ended up preferring the black links in the right-hand column because I felt they gave a bit more focus to the center column. There are some DU3 pages -- for example, the home page -- where many of the links are black (including the LBN section on the home page). That never seemed to cause a problem before, so I didn't think switching it up on DU4 would be too big a deal.

If you use Skinner Mode, the blue links are retained in the right-hand column to match the way they are on DU3.

Finally I'll say that the name of the game on DU4 is customization, so we could potentially include an option in Account Settings which would turn those links blue. (We wouldn't be able to do this immediately though due to other priorities pre-launch.)