All-caps are a bane to all existence
I do not understand the fixation on making navigation headers all-caps. It's been recommended time and again that making things in all-caps decreases usability due to removing shape cues from the words (since each letter is now the same size) -- there is a decent writeup on this on UX Movement[1]. While other studies show that this is simply due to practice/learned behavior[2], it still results in increased time spent reading and comprehending the title bar to determine areas of possible interest.
Also, I'm not sure if you're being cute and changing the bar text based on IP geolocation, but the title reads "DATA CENTER" for me (I'm in the US). Since I'm visiting a co.uk site, I'd rather see the British spelling of "Data Centre" in the navigation bar.
As for positives, I do like the reduced clutter, and article images when done right can help provide a glimpse at what the article is covering as well as setting the overall tone of how the text is read. Giving an option for logged-in users to disable it may be for the best, however, as by looking at the comment thread not everyone feels that way. I have no opinion on the visited link color; I'm rather young so I find the grey just as easy to pick out as the former red (whereas the grey actually de-emphasizes the article whereas the red makes it stand out more, I'm guessing this was the basis of the change).
[1] http://uxmovement.com/content/all-caps-hard-for-users-to-read/
[2] http://www.microsoft.com/typography/ctfonts/wordrecognition.aspx - This article cites papers by three authors Woodward, Smith, and Fisher. I was able to find the Smith and Fisher papers freely available online via a quick search as well.