All of the great OS level changes that were supposed to come with Leopard are conspicuously absent. No ZFS and no resolution independent UI means that the two most revolutionary features with the most implications for the future of the platform are gone. I was seriously excited about Leopard, but every day that we get closer to gold master means that these will not be in there.
The other things, Spaces, even time warp can be done as applications sitting on top of the OS (well time warp would require some kind of version control like svn but still, it's not nearly as great as having a display of incredible resolution that won't require that my old man eyes have to be 1 inch away from the screen).
Unless the surprise feature is an iPhone SDK, a crippled Leopard won't save apple from the whole bad decision iceberg that is smashing into their titanic.