I love me some Word/Excel/PowerPoint (even the much maligned Ribbon), and Google Docs doesn't have anything close to Office's feature set. That said, the ability to edit a document simultaneously in Google Docs is its killer feature. The UX for this feature in Word/Excel (haven't tried PowerPoint yet) is nowhere near as good, in my humble opinion. I find myself doing collaborative composition in Docs and then, when necessary, moving to Word/Excel to finish editing. (Also, it would be nice if I could edit spreadsheets and presentations online in SharePoint.)