whow! I can see a lot of people could use a chill pill
Seriously? Are we that desperate for a new OS? What SO wrong with Tiger? I for one will gladly wait until June if that means a clean, stable 10.5.0.
As of now I'm happy with Tiger, I can say that I'm waiting more for 10.4.9 than 10.5.0

As for the top-secret features, I don't really know, usually Apple blows our minds with stuff we never thought about so I wouldn't say that the secret features that Jobs refered in WWDC 06 are a bunch of crap, I just don't bother trying to imagine what they are.
One thing I really want to see in Leopard is how Apple is giving use to Core Animation, I'd like do see folders and files flipping around (like dashboard widgets) to set their preferences, maybe the first introduction to 3d elements in the desktop, something different you know?
As for the release date... I don't have a clue, no one does, and ultimately that's my point, all predictions can be right or wrong ( although some seem more right than others, my vote goes to June ).