Okay, Benjamin, I think you should add a reference to the article in Oliver Bell's blog. I know there is a reference but the article becomes a bit esoteric otherwise.
Anyway, for those of us who don't believe in the OSP we found a nice Slashdot post today:
http://developers.slashdot.org/article.pl?sid=08/02/17/1911249
Developers Warned over OOXML Patent Risk
and the one and only Pieter Hintjens contributed this here:
It appears that Microsoft has about 280 patents around OOXML and related technologies. It also has a large number of patents that read on ODF. We're making a list of these and hope to be able to publish them soon.
There are also several patents from third parties that read on OOXML, and in theory ISO should halt the process while these are examined and cleared. It looks like ISO won't do that.
Microsoft has several techniques to keep OOXML a captive standard [digistan.org] controlled by a single vendor. Complexity is one. But patents are the very best technique.
Note also that OOXML's complexity is mostly because it's a dump of a legacy format. Some upcoming MS ISO proposals are very clean technically, but also very heavily patented.
It seems clear that the OSP is worthless for GPL implementations, the biggest threat to Microsoft.
At the same time it's worth noting that the format being voted on by ISO is not the format implemented by Office. There are over 2,300 changes and the two formats are not compatible. The reason for pushing for ISO standardisation is to let MS market their formats as "standard", while in fact implementing non-standard vendor-specific formats. And then, using patent threats against anyone who tries to reverse-engineer those.
It's a nice con trick. Many national bodies have realized what's going on but many are too corrupted or too ignorant to understand.