I have worked in enterprise for 20 years and have always been watching the vast majority of my colleagues (by the numbers) struggle to make anything but basic use of Office. My experience has been that there are a few advanced users who enjoy the mastery of it enough that they know it inside out, but the majority of enterprise workers really just do pretty basic stuff with it.

Meanwhile, the killer app of G Docs (collaboration) is a very frequently unanswered need. People emailing attachments with ridiculous names like "contract_v2_final_finalforreal.docx", making conflicting edits that cannot be reconciled, carrying USB sticks around because their PPT presentation is too big for email and they can never figure out how to use shared folders, etc.