I recently took a look at the Document Information Panel functionality in Word 2007 which allows you to provide a custom form to enable metadata editing for documents stored in SharePoint and encountered something unexpected.
You can actually customize this Document Information Panel by plugging in your own Document Information Panel (DIP). A Document Information Panel is actually nothing more then an InfoPath form - see InfoPath 2007: Customizing the default Document Information Panel.
SharePoint autobuilds a DIP for your document metadata and seems to work without an installation of InfoPath on the client. But what if you want to build your custom Document Information Panel using InfoPath? This where things get ugly - like this guy noticed as well - All about the Document Information Panel and InfoPath issues. Whenever you are going to use a custom Document Information Panel - you will need to have InfoPath installed on all the clients.
This is actually explained on this page - Microsoft Office Professional Plus 2007 Suite Comparison - all the way to the bottom - there is a footnote which contains some very important information.
|Features and Benefits ||Office Standard 2007||Office Professional Plus 2007||Office Enterprise 2007|
|Complete, collect, and organize Office InfoPath e-mail forms in Office Outlook 2007.2|
|Host embedded, fully customizable InfoPath forms in Office Word 2007, Office Excel 2007, and Office PowerPoint 2007.2 |
|Complete forms in Programmable Task Panes. 2|
|Complete custom fields and execute custom business logic in Document Information Panel forms.2|
2 These capabilities require that Office InfoPath 2007 be installed on the client computer. Office Professional Plus 2007 and Office Enterprise 2007 include Office InfoPath 2007. Organizations that acquire other suites can purchase and install Office InfoPath 2007 separately.
As I stated in the title - the devil is in the details ... sometimes even in a footnote.