But it's still the Web
Despite offline access, it's the Internet connection that makes Chrome OS useful. There will be a file system and media player to let users manage movies, music, and documents, but to make your files accessible anywhere you need to send them to the cloud. For photos, Google offers Picasa, but there are plenty of choices including Snapfish and Flickr. Even though it's a Google computer, you're not restricted to using Google cloud services.