You may have seen the news that people like Russell Shaw discussed that there are some Mac incompatibility issues with Office 2007 file formats. I am confident that someone will come out with a fix like Microsoft did for Office 2003 and if not there is always OpenOffice as an option. On the mobile side of the house, at this time I am fairly certain there is currently no mobile device application that will read these native Office 2007 Open XML formatted documents. This includes Office Mobile on Windows Mobile devices, Documents To Go from DataViz, and the Quickoffice suite. Even the extremely powerful SoftMaker Office products need to be tweaked to support the new file formats. The ClearVue Suite is included with many Windows Mobile Smartphones, but I did not find any support information for Office 2007 there either. I am sure that developers are working on updating their program to work with Office 2007, but mobile device users will want to be aware they may have issues reading documents sent to them on the go at this time. Hopefully, at least the document viewers will get support quickly as that is a more common task on a mobile device, rather than full document editing.
I am a bit surprised that none of the existing mobile operating systems or 3rd party applications are compatible at the launch of Office 2007 since a public beta has been out for a few months and this really should not have come as a big surprise to developers.
I received word from Microsoft's Mobile division that they will post an update by the middle of 2007 for support of the new XML file formats for Windows Mobile 5.0 devices. Crossbow devices, aka Windows Mobile 6, will include support for these file formats as these new devices are not scheduled to start rolling out until mid next year. A public beta of the update is planned for the 2nd quarter of next year.