I have a special, exclusive knowledge of Leopard's secret features.
The Leopard will support:
(i) Super Growl technology. You will be awakened by thunderous sounds every day at 7 am even if your computer's speakers are on mute. The built-in i-sight would also allow to trigger the same response upon seeing an unindentified intruder (customizable, of course).
(ii) Cocoa will be Carbonated, even if you do not like that.
(iii) A new USB accessory will be announced: the iTail. Coming in two flavors: yellow with black stripes or black with yellow stripes, the iTail will be self-powered by a USB port. It won't do anything, but hey - it is self-powered! Speculatively, third parties will soon follow with the announcment of a coffee stirrer attachment that fits on the end of the iTail. Since it stirrs Cocoa too, it will be expected to cause quite a stir.
Oh, by the way, a bluetooth version of the iTail is apparently in the works...
(iv) Portables will be able to accept meat in the CD slot to keep the battery recharged. Rumors say that Steve Jobs first wanted the MacBookPros to go as far as to have an option of being able to hunt autonomously in the new, Sleep-Walking mode, but the idea was "Self-Steved" upon demoing a working prototype, which turned out rather disturbing. Still, a new disclaimer will be added to the EULA: Apple inc bears no responsibility for the accidental inserting of fingers into the feeding slot...
I think that's it for now. The info is free, but donations are accepted