"Google welcomes the ISO decision to not approve the fast track of Office Open XML (OOXML) proposed standard DIS 29500 (ECMA 376). Our engineers conducted an independent analysis of the OOXML specification and found several areas of concern, which we communicated both to the ISO and to the public."
http://google-code-updates.blogspot.com/2007/09/google-welcomes-iso-decision-on-ooxml.html