I received this response from the uk's BSI after enquiring on the commenting process.
Thank you for your enquiry regarding the recent fast-track submission, ECMA 376 (ISO/IEC DIS 29500 OOXML). The formal commenting process for this ballot ended on 30th June.
The ISO/IEC JTC 1 N8455 (JTC 1) 30 day review of ECMA 376 (ISO/IEC DIS 29500 OOXML) resulted in comments from 20 National Standards Bodies. JTC 1 and the International Organization for Standardization (ISO) authorised the ballot to progress to a five month ballot.
To handle the large volume of comments expected in the UK, IST/41, the UK technical committee, established IST/41/-/1, a special technical panel consisting of 30 experts. The panel carried out a detailed technical review of the specification, and considered the comments submitted on the Draft for Public Comment. Their findings were fed into IST/41 to propose a UK response and the matter was referred to the parent committee ICT/-/1 to agree the final UK vote.
The UK position will be made public after the closure of the ISO ballot on 2nd September.