There have been a lot of discussion about B103 and the consequences of primary ODF vs OOXML. The National IT- and Telecom Agency have prepared a lot of analysis, documentation, tests etc. about the two document standards.

The latest are guidelines for the public instutions, who most from the new year be able to RECEIVE documents in the two formats. The guidelines can be downloaded here. Epecially the chapter about tendoring is interesting.

I use MS Word 2003 and can read OOXML documents. If somebody sends my ODF-documents; I must forward it to our support-departement, who must convert it to .doc-format for me.