So this whole thing really irritates me.
Having said that, I think that modernizing Wikipedia or MediaWiki is a an interesting idea (although probably not a priority), and this is actually a decent starting point for discussing how many of the new (mainly, but not entirely, stylistic) UI/UX trends (principles in a few cases I guess) could be applied.
I mean obviously their nav takes up more space than necessary and we don't need Wikipedia's logo to look just like WordPress's, but the minimalism, alternate typography of some sort, monochrome icon widgets, etc. are apparently now required in order to qualify as contemporary design. And the connection clouds and highlighter quote idea is cool. And it probably wouldn't hurt to remove one or two of the buttons on the editor or move them to an advanced section, or spend an hour or two making the editor looking more contemporary.
In case anyone actually reads this, I have a question. Is the thing where buttons and controls are monochrome icons (and usually with no 3d appearance), is that going to stay? I mean, is there a reason you can't have multiple colors in icons now? Also it seems a lot of times you don't get labels on buttons anymore (I know, tooltips). How much of this stuff is likely to stick for the next 5, 10 years, or is it just a short term fad? I mean I coded a UI recently for a component platform thing I am building (actual functional software platform, not pictures) and it had multicolor traditional icons on normal 3d buttons with labels. This UX guy saw that and said I was 'completely out of touch'. So I took the labels, 3d and colors off the buttons.