I added a background image with a grid that extends 80px from top and bottom. There's also a small margin/padding/border reset and doctype just to make sure defaults and quirks aren't messing with anything.
To continue down this path of the "natural" way to vertically-center, font-size must also be explicitly set. This works http://jsfiddle.net/nJy8t/3/ . Though it's certainly not without it's flaws (we lose font-size cascading).
that solution
1. only works for text, which is part of eranation's rant.
2. only works if you know the exact height of the container.
3. isn't even centered: http://i.imgur.com/lz8Mq.png