I would very much like to see cloning. I am thinking of using OO in my research, and there I find that I often have a lot of inter-related topics. Currently I gather this information on a Wiki, but I find that I generally work hierarchically anyway, so I would like to switch.

One additional note that is related:

It would be excellent if, when a link to a local file was embedded into an omnioutliner document, the contents were displayed using Quick View. Right now, you only see the full text of the link "file://localhost/Users/...", which is fairly uninteresting.

The reason that I post this here is that I often have shared data which takes the form of an OmniGraffle diagram, or some other, external file. Using links I can easily embed this in multiple places, but then I lose the ability to view it inline, which seems unnecessary.