ClockworkMod has rolled out Carbon Beta 3. It includes Box Cloud backup/restore support now. If your device is not rooted even you can install this app and can backup your data. In beta 3 Koushik Dutta has also an option by which you can also cancel backup or restore in process. Now you will also see backup/restore process in Notification area. Along with above changes there are also Performance enhancements and bug fixes and new bugs also.
Koush, in his Google+ post, says the beta should stop working on Jan. 30, by which time we should see the app in Google Play, with free and premium versions.
For More info: Google+