On a similar note, can someone explain to me what the point of the .docx format is, other than being a pain in everyone's ass?
Well they moved from completely proprietary encoded bull**** to XML proprietary bull****

Also I think the old .doc (and related files) were built within a certain set of limitations (for instance old Excel documents could only be a certain length before it would ...stop). So they made new ones with new specs that didn't have the old limits. Its not a completely bad idea either...different versions of Office, despite having "compatible" file formats weren't always 100% compatible. Between Office 97 and Office 2003 was sometimes interesting when doing more complex operations.
As far as I'm concerned...once you're done with the source file it should be compressed down into a presentation format...like PDF.