Single vendor suicide
This ISO thing is a side issue. The problems with OOXML remains, it originates from a single vendor and that vendor claims IP rights over it. All products that use it, need a license from that vendor, and so any government that uses that format will be at the mercy of that company and it's license policy.
The whole ISO thing is something of a joke, nothing but a play on the word 'standard'. If ISO didn't endorse it, MS would simply find some other standards body to endorse it. Simply so they can say it's a 'standard'.
But there's nothing stopping them creating OOXML+ with Microsoft extensions, nothing to stop them changing the license terms for each revision, and no reason why anyone would lock themselves into a single supplier situation. The play on the word 'standard' doesn't fix anything.
What next? Will they get the XBox360 declared an ISO standard to try to fix it's poor sales? Will Microsoft 'Bob' make a comeback as ISO standard 294857. If they can simply stuff the ballot with Microsoft Certified Partners, then both these are easily doable, but neither would fix the shortcomings in those products.