It would be great if I was able to specify that a pinned application should only be shown on a specific desktop. My use case: I have different virtual desktops which I use for different purposes (e.g. browser, PIM, shell, ...), and on each of these I find a different set of applications useful, so I would like to have different sets of pinned applications for each desktop.
Use activities - and then pin things to the relevant activity
OK, but can I drag&drop windows or objects between activities?
Yes, e.g. with the Activity Pager.