Why aren't links highlighted in some way? (Underline and/or bright blue color are common ways).
As it is now, if it wasn't for most browsers coming with a "underline links" option or "use browser's links colors" set by default, lots of people would fail to see links all over the site.

I've actually grown used to such a clean look. For instance, the menu on the left is almost crying out to be clicked so this comment doesn't really apply to it. Same with the "options" in the message box, for instance, (show thread, link, etc) since they are isolated enough.
But for links inside posts there really should be some sort of highlight other than the one forced by someone's browser (I always liked the blue color, no underline style... seems "Simple" enough ).

So I'd like to suggest that the A tag be hilghlited in some way, by default. This setting could be overriden for some classes, where it is not so needed (like the menu, for the reasons stated).