If I had to say it in just one word, that word would be Elegant.
It's very nicely done, well thought out, and it smells of careful planification.
Just one thing I like less: On sites with few links in the menu, I prefer that the a:visited state of links stays the same as the a:link (in sites with many links, like news sites, quickly pointing out the links already visited DOES make a difference, and it helps a lot).
In this case, visited ones turn to gray, which is OK, but being just a few sections I can remember which ones I already saw and still have the menu in one colour. But, hey, it's only a matter of personal tastes. Since you, on purpose, differentiated a:link, a:visited and a:hover, I must conclude that you like it this way.
So, on the whole, I liked it a lot.