I had described my use-case of folders sync before (I synchronize my PPC using WinCE file system plugin), often synchronize operation lasts long enough and user should sit before the screen and wait for "do you really want to delete the 100 selected files...." to press "yes!" and finish the synchronization. This could be a kind of annoying, if you can’t just start the process and forget it until its end.
I think it would be handier to have an option to ignore deletion confirmation. Yes, I realize, that the third option for "delete" operation would look strange on such a small dialog appearing after pressing "synchronize"

Thoughts?