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
Give Notes calendar users the option to mark calendar entries as also being Out of Office (OOO.) Then post an entry into a central OOO calendar (Native and Web.) I have run into several organizations that labor over creating a seperate Notes database that simply shows (manually entered) OOO entries ...