Up close: Apple's Mac OS X Although Jobs noted that some features of the company's next operating system, which is due out sometime early in , would remain secret for now, he did take developers through a tour of some of the software's new features. Last week, Apple officials offered guided tours of the company's new Xeon-based Mac Pro desktop computers, conveniently offering a closer look at Leopard for those lucky few on hand to check it out.
I found a better post. He has tested the ISO file and also provided the installation tutorial: I used imageusb and installed.
Apple WWDC 2007 - Mac OS X Leopard Introduction