I'm not sure why OOXML is listed as a contentious issue. Clearly, as a format it is contentious, but both Go-OO and OOo have OOXML support, and indeed it's Sun who are putting the greater effort into it.
At this point, it's pretty difficult to see what the right way forward for the suite is. A bit of competition probably wouldn't do it any harm, but that's only going to work if people are making or seeing a choice. At the moment, Go-OO isn't really a fork because people using it don't realise they're using it.