I just saw this on Stephen McGibbon's website: http://notes2self.net/archive/2008/03/25/czech-republic-votes-to-approve-dis29500.aspx

The Czech Republic has decided to change their vote to "yes" for DIS 29500. The Czech national body (led by Jirka Kosek) played an important role in the technical review of the spec and also with their contributions at the BRM towards improving the specification. They had a couple interactions with Ecma leading up to the January posting of the proposed dispositions and helped ensure that their issues were properly addressed.

It looks like that coordination really paid off, as they now feel Open XML is ready to become an ISO standard.