Comment 5 for bug 237064

The new OOXML files (.docx, .pptx...) are zipfiles indeed. I can currently test only for a .pptx file I have, for which "create archive" is missing too.

Unlike I said before, not all MS Office files lack the "create archive" option. For me, it happens only for .xls ones, for which the "Extract here" is completely nonsense (indeed, file-roller shows an "archive not supported" error). .doc and .ppt work regularly instead.