With the latest changes to the specification it is bringing the standard close and closer to the finish line. This is a great thing not only for Microsoft but for the community. To have one standard that allows us to represent information in our word / calculation processors (i.e., Word and Excel).
I think that it is very important for us to consider the value of this. Like it or not we have Word and Excel tightly integrated into our business processes. Often times our business users demand these tools so they remain productive.
The proprietary artifact formats that these tools leave behind have given architects challenging obstacles. This is particularly true in the realms of integration. Now if we have an XML standard that defines the information, it makes the data all that much more interoperable with our business processes.
Architects should consider how OpenXML will impact their IT Systems and think through some of the new opportunities that can arise with this new format.