Toward Interoperability
Interoperability is definitely the buzzword-du-jour at the moment. It looks like Microsoft have finally bowed to (mostly governmental) pressure and are going to use an XML-based file format as the default for their next release of Office. While there's no mention of them adopting any pre-existing format (Us?? Use a format we don't control??), they are going to publish this new format on a royalty-free basis. This can only be a good thing, as it will hugely cut down on the amount of time spent reverse-engineering closed formats, which will be a huge boost to other office programs.
It's not quite as good as if they had agreed to adopt a pre-existing open format, but this is definitely a step in the right direction.