URL says maintenance, although I'm kinda surprised that a company on Apple's scale can't manage rolling restarts to present a zero-planned-downtime face to users/devs.
Could be they're updating the pages for WWDC 2013. I want to say last year it was released on April 25th.
What's the fun in a rolling restart. It's probably Apple strategy to bring down the site and get some speculations up every time this happens.
You may have a point. It's not how I would do things but maybe that's why I'm not the boss.