I am personally sad that this happened, though considering the composition of the committee (a seizable number were Microsoft dealers/partners approx 7 of 12). I hope to get more details on this.
The case for not adopting OOXML remains simple. It is not as open as it is made out to be by the main proponent(s). (visit http://www.noooxml.org/ for more info)
As far as I know, only Microsoft Office 2007 can save documents in this format.
If this standard is to be truly open, it needs to be vendor independent among many things.
More details here: