As an Office customer and a Dropbox customer, I can't help but have mixed feelings. Office already has "direct" OneDrive integration and it's pretty useless, how could it be any better on Dropbox?
The whole thing about Dropbox is that just works. Files are files, folders are folders, if I move them about they move, etc. The only problem with Dropbox and Office is how Office locks the files so they're only synced after I close the Office program, not after every Ctrl+S. Fix that, and it's integrated.
The whole "save in the cloud" nonsense that desktop Office programs have these days feels like a mistake. I can understand how with iOS's "no files" design, this is the only way forward, but on desktop? Please let it stop.