It includes word processing, spreadsheet and presentation modules, and comprises GUI, format and API specifications. Like both ODF and Office OpenXML, it is another "XML in a Zip file" format. ...

From what I understand, UOF was developed with less compulsion to follow the lead of Microsoft Office and its fifteen years of accumulating features, allowing UOF to be simpler rather than slavishly faithful to (and therefore constrained by) what has come before. I'm also told that the UOF format is based on existing Web standards, such as SVG....

There is already an effort in place to "harmonize" UOF and ODF, and from what I understand that process should be less challenging than making ODF and OpenOfficeXML play nicely together....Third, what of Office OpenXML? Implementation of UOF will continue the trend away from proprietary, "lock in" products, and towards an environment with more competition, more variety, and more freedom for end-users. Presumably, the proliferation of compatible open format alternatives will place added pressure on OOXML to become increasingly open and competitive in order to be relevant.

All the plotting and planning here in the US was for absolutely nothing. ODF wins.