The most commonly used product family today, all categories included, is the MS Office product suite. It has been around for more than a decade, but today it is hard to find an organization running anything older than MS Office 2000. The fact is that this product suite works so well that a lot of organizations still use MS Office XP or 2003, while an increasingly number have upgraded to MS Office 2007. It should come as no surprise that MS Office 2007 has the best integration with SharePoint 2007, and this is by design! A lot of features in SharePoint 2007, such as workflows, simply need an Office version that is built to support that type of functionality; older Office versions will have limited, or no, support for a number of SharePoint 2007 features.
In Chapter 1 there is a table that compares the SharePoint functionality among different MS Office versions.
Do not expect to see any updates released for older MS Office versions that will extend their support for SharePoint 2007. Except for one thing (and this is not really a SharePoint feature): support for the new XML-based file format, introduced in MS Office 2007, through a free add-on named Microsoft Office Compatibility Pack(MOCP). It is important for SharePoint users, since it will allow users with older MS Office programs to work with documents created with MS Office 2007, also for documents stored in a SharePoint document library. To download this MOCP extension of MS Office XP and ...