Dropbox is a great tool for synchronizing your data across multiple machines, but it still lacks the ability to edit documents with it's own set of tools. They are now tackling OneDrive's Placeholders application and Google Drive with their latest update that is rolling out to business users first, and then will be available to all Dropbox users. It's called Project Infinite and it's a nice alternative. It will roll out as Smart Sync, but there is no word yet on timeline.
While the biggest need for Smart Sync has come from our business users, the positive response we’ve heard from individual users has led us to explore ways to make Smart Sync available to them in the future as well. We are looking into technical requirements for individuals and exploring go to market options based on customer and user feedback, though don't have a specific timeline.