After a couple of months of not updating, I updated my local copy of WOU to 9.3.1 from 9.2.1.
Then, after successfully running the update-download, the folder "wxp" was still located under "client", although I have "Clean up download directories" checked.
Is this by design, a bug or a side-effect of the "superseeded"-changes?
Checked software-versions are Vista x86, Windows 7 x86+x64, Office 2010 eng+ger.