Yes, OpenXML import and export could be integrated into OOo [Open Office] today but engineering politics and Sun’s manipulation of the project to foment a document format war have kept this functionality out of OOo, doing nothing except harm users that need to seamlessly integrate with MS Office environments.
I’m inclined to agree. If niche player DocumentsToGo can implement this feature, is it so hard for Open Office? I doubt it. Now, I am sure that any such feature would not be perfect – but import/export features never are. Equally, I’d expect that it would work fine with the vast majority of documents that people email back and forth every day.
See also A Plague on both your houses.
PS Microsoft could also do a much better job with ODF import/export. These problems are more political than technical.