Adobe's Portable Document Format (PDF) is a de facto standard on the Internet. The format is supported on most computing platforms, and the ability to read and write PDF is common, driven by Adobe's early willingness to release full details of the specficiation. Subsets have been standardized by the ISO, such as PDF/X for printing and graphics, PDF/A for archive purposes, PDF/E for the exchange of engineering drawings, and PDF/UA (pending), designed to be a universally accessible form of PDF. On January 29th, Adobe announced that they planned to release the full PDF 1.7 specification for standardization, a response to earlier plans by Microsoft to submit its XML Paper Specification (XPS) for standardization.
In future, PDF is likely to have an XML incarnation. The Mars project aims to make "an XML-friendly representation for PDF documents."
Given that Adobe is standardizing PDF through the ISO, it's highly likely that, once Mars appears on the scene, they will attempt to standardize it through the same body. When that happens, will the same groups opposing OOXML dig in their heels because ODF is already an ISO-standardized XML document format?
Somehow I doubt it...but, you tell me.