Sure, Microsoft's online Live/Mesh/Azure strategy is just a tad less complicated than n-dimensional string theory, but it looks like when the next version of Office (14) ships with it's GoogleDocs/Zoho competing Office Web, it will include support for not only Mac OS X... but for the iPhone's MobileSafari browser as well!

According to Macworld, neither release date nor price point are known, but it should be a companion to Office 14 which is slated for 2009(-ish?)