While details on Apple's new OS (Leopard) have been fairly skimpy, Wired got their hands on the WWDC build (9a466) and posted a review and some screen shots.
Shortly thereafter Apple laid the smackdown on them:
UPDATE, Friday, 9:40AM: Apple has requested that we take down these screenshots of Leopard due to copyright issues. As a result, we've removed the screenshots of the new screen savers and the iCal application. However, we're leaving up the remaining screenshots of the desktop and Safari, which aren't exactly super-secret, with our commentary.
Luckily, the Google cache still has the six screen shots, if you're interested.