Amazon unveiled its all-new tablet computer today, adding the more robust Kindle Fire to its well-established line of Kindle e-readers. The Kindle Fire isn’t merely a copy of Apple’s dominant iPad. Instead, it’s far smaller and cheaper than its main rival. Powered by Google’s Android operating system, the Kindle Fire provides a platform for games, movies, music and other applications. Unlike the current iPad, the Fire doesn’t need to be backed up on a PC. Instead, it backs up its content wirelessly on Amazon’s servers. “That model that you have to back up your own content is a broken…