The important thing is this: The ISO Delta is completely irrelevant to the marketplace. It is not implemented in the shipping Microsoft products. Microsoft may choose to implement some portion of it in some future release of some product, or they may not. Given Office’s release and adoption cycle, it’s very unlikely that any pieces of the delta they decide to implement will be widely deployed in anything less than five years.
Thus, if you write OOXML software and you generate ISO-Delta markup, it won’t be usable by the deployed base of software. In fact, we have no information as to how gracefully Office will react; will it bypass such markup or explode messily? I’m not optimistic. So, implementors should not generate ISO-Delta markup.
If Bray is correct, the whole purpose of a standards organization has been defeated. It is a shame, a real shame.