In the package explorer, you can click the top right down arrow and select "Filters ..." and filter out java elements, fields, import declarations, etc. Subsequently, only packages and classes should appear.
This will work on Helios, but I know that in the old version of Eclipse Mylyn did not allow me to change the filter while I was "focused" on the task. However, I could make it work by changing the filter before putting any task in focus.
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