The other day I noticed a small but noticeable change with the Office Web Apps that I use on my SkyDrive. Previously, you could view office documents in the Office Web Apps, and viewing PDFs relied on your browser's built in PDF viewer or plugin, in an embed on the SkyDrive webpage (it was sorta like viewing an image).
However, a few days ago I noticed that PDF files now open in the Word Web App in reading view, with the ability to edit the PDF by converting it to a Word document. The Word Web App acts much like it does when you are viewing a Word document, with a few changes in wording and a small icon change at the top of the page where you have a PDF-like icon on the download button.
As said before, the Word Web App can now view PDFs and edit them as well by converting them to a Word doc before editing. However, the Word Web App has limited editing capabilities and therefore it can't edit complicated documents. in addition, converting from PDF to Word can also cause issues. That's when you'll get this error:
You can choose to view the converted file or go directly and edit it if you want. If you don't like the converted file, then you will always have the original PDF file that you had before, untouched.
Now, only if the Office Web Apps team could release support for headers and footers.