To allow us to really use them as replacments for Office, it seems to me like we'd need to be able to natively read/write:
Word Perfect 9 - 12
OpenOffice (not just ODF)
For many users, It's easier to move from Office 2000/2003 to Symphony than to Office 2007, but it would be almost transparent if IBM made an optional menu (File, Edit, etc) that mimicked the Office 2000/2003 menu structure. Corel does this with WordPerfect Workspace Manager, and it's very useful. Link
If you receive a document from a client that has worked in a different Office package that supports Images and other information in the header/footer area, that document will not work as it should. For example I have such a client that has a logo in the header of a ...