Office 2007 migrations in advance of SharePoint

A few customers have recently pointed out to me that they are going to have a significant number of early adopters of Office 2007 in advance of their migration to SharePoint 2007, this will be particularly true where SharePoint is used at an enterprise level.  Previously I had assumed that SharePoint (being server side) would migrate in advance of Office.

This got me thinking about how little I had seen from Microsoft about the issues of compatibility between mismatched versions of SharePoint and Office.  As my area of interest right now is Office 2007 used with SharePoint 2003 here are a few of the issues I can guess (possibly incorrectly) at and there will probably be a great many more:

1. Groove 2007 only provides support for offlining document libraries whereas the previous version also supported discussions and some other tools.  So users of Groove 2007 are going to see reduced functionality – assuming Groove 2007 works with Office 2003 at all. 
2. Although some of the missing functionality in Groove 2007 migrates to Outlook 2007 this migration will only be relevant when the SharePoint 2003 environment is migrated to 2007, in addition it’s only likely to be suitable for users of Groove within the enterprise.
3. Excel 2007 doesn’t support bi-directional replication of lists and publishing of lists to SharePoint 2007,  although existing lists created with SharePoint 2003 will continue to work.  I am assuming that Excel 2007 when used against SharePoint 2003 will have the same limitation. So users will see a loss of functionality, similar functionality will be available in Access 2007, ie the ability to publish tables to SharePoint and take bi-directional replicas offline, however this functionality in Access 2007 will only be relevant when the SharePoint 2003 environment is migrated to 2007, and of course you need to have a SKU that includes Access.
4. I don’t expect that SharePoint 2003 will support the new Office XML file formats for searching, and document property promotion and demotion.
5. In SharePoint 2003 documents were checked out to a hidden area on the server and so could only be worked on online.  SharePoint 2007 and Office 2007 now check documents out to a hidden directory under [My] Documents, I am not sure which behaviour if any will work with mixed versions
6. Word 2007 includes a rich interaction model with SharePoint – which features of this will work?

If anyone knows of a good information source on this topic, please leave a comment, or if you know of any issues I have missed or issues I have highlighted incorrectly please leave a comment as well.