I just saw that the Novell folks have released a version of OpenOffice with support for the Ecma Office Open XML formats (http://download.novell.com/SummaryFree.jsp?buildid=ESrjfdE4U58~). They announced this work awhile ago, but this is the first chance folks have had to actually download the builds and try it out. Very cool stuff.
So at this point we now have a few options for applications that support Open XML on a couple different platforms. We'll see more popping up over the summer too (for example Corel as well as the Mac version of MS Office).
I think at this point we can really move onto more productive and collaborative discussion and admit that we are no longer in any sort of "file format war." If we ever were really in a war, it's now over, and both sides are winners. Over the past few years, we've had two important file formats come into the market, OpenXML and ODF. Both were designed for different purposes, and both have been valuable additions to the market. Now we can also say that we have multiple implementations of both formats.
When discussing file formats, there are a number of things that can set one apart from others such as performance; file size; security; accessibility; extensibility; and support for different types of functionality like formulas, formatting, drawings, etc. Before looking at any of those things though, there are some fundamental issues that may be important to see addressed. These issues have recently been called out by various government bodies (like departments within Massachusetts, Minnesota, Texas, and now California).
The big reason people are excited about both ODF and OpenXML is that they enable the following:
It's those three points that really make, both OpenXML and ODF interesting formats. You now have OpenXML supported by multiple applications on multiple platforms, and you have the same with ODF. There are definitely still some growing pains to go through. The tools that support the ISO ODF standard aren't yet fully compliant, but I think we're heading in the right direction. The same will be true for the OpenXML support.
Let's keep the momentum going and focus more on what we can do with the formats. I'm going to start pointing out solutions that other people are building around Open XML using the "3rd party tools" tag: http://blogs.msdn.com/brian_jones/archive/tags/3rd+Party+Tools/default.aspx