Dropbox integration is something I've come to rely on in Android - I honestly don't know if I could do without it. Whether through the native share interface, or via direct integration with a particular app, Dropbox is my go-to for cloud storage, and has been for a while. Mobile developers wanting deep Dropbox sync integration in their apps, though, have generally been left to their own devices, necessitating the creation of custom-made solutions for those wanting to go beyond simple upload and download.
That all changes today, though, with the introduction of the Sync API. Its job is relatively simple: if you're using an app that either pulls files from, or send files to Dropbox, the Sync API will allow that app to hand off the job of making sure everything gets from point A to point B (and back again) correctly to Dropbox. And that's sort of a big part of what makes Dropbox so great - the reliability of syncing. So, if your user loses connectivity while attempting a sync task, Dropbox's handy new API will ensure that the sync actually completes when the connection returns, just like it would with a sync operation in the Dropbox app.
While the implications for the reliability of basic cloud storage integration are important, this new tool could allow for all sorts of neat implementations of Dropbox's robust file syncing capabilities (game saves, anyone?). Just another feather in the cap of our favorite cloud storage service.