As promised by Brian Jones, finally the project (under a liberal BSD-like license) to convert Microsoft Office binary format (doc, xls, ppt) to the Open XML format (used since Office 2007), named b2xtranslator, has been initiated on SourceForge. As I wrote before (on Google Code Project Hosting vs SourceForge), it'd be fantastic if Microsoft would have placed the project on Google Code instead of SourceForge (but it is Microsoft we are talking about). As of now, download is not yet available as the project is still in its very early stage.
Many office suite developers have an interest on Microsoft Office file format because it is widely used. The description of the format itself can be obtained from Microsoft since quite some time, however only with the b2xtranslator we will start to see an implementation which is "blessed" by Microsoft.
Technically, there are two slightly disappointing points with this b2xtranslator project. First, it is not an implementation used by Microsoft itself in its office suite but rather an independent one. Second, it requires .NET framework (exactly as I have predicted). For the former, again it means playing the same cat-and-mouse game since there is no guarantee that the translation is fully compatible with the code in the real Microsoft Office. For the latter, well I leave to you, the readers, to reach your own conclusion. Of course there is Mono (which, by the way, is used to integrate odf-converter in Novell edition of OpenOffice.org), but you know well where the discussion would lead.
As usual, let's wait and see.