We don't have discreet control over workset visibility in linked files on a view by view basis yet (not in RB9 either). We DO have the option to specify what worksets shall be linked in when we import the file initially, project wide mind you. When you use File > Import/Link > Rvt choose Specify.
Revit will offer you the Workset dialog to choose which worksets to open or close.
When we need to change these settings we have to use File > Manage Links > then choose Reload From
Now specify which worksets you need again.