TC46 has made available initial working drafts of the XPS standard that the committee is working on. You can download copies from the TC46 activities page on the Ecma web site; here's the link:
This version doesn't have any substantive changes from the documentation originally submitted by Microsoft, the main purpose of the document is to enable referencing and discussion of issues and work items with a consistent numbering of clause and sub-clause where the content is already structured according to Ecma's style guidelines.
Here's the explanation of the major changes from the documents front matter:
This document is "a work in progress". It is the starting point of discussions within Ecma Technical Committee TC46. It was adapted from the original XPS specification as published by Microsoft, to match standards editing style guidelines more closely, especially in the area of distinguishing between normative and informative text. A number of formatting and textual issues remain to be addressed, as well as the bulk of the work of TC46 in amending the text to meet the scope and goals of the committee.
If you have comments or feedback on the specification, the committee is recommends referencing this working draft rather than the Microsoft provided documentation (available via http://www.microsoft.com/xps).