WebDAV, email attachments, and FTP access is not on the current feature roadmap, and likely won't be for the foreseeable future.
No hard feelings. This isn't a "no it'll never happen." But we're currently working hard delivering other, equally exciting features.
Not using Dropbox yet? See how Dropbox makes syncing files easy.
Among the thousands of Dropbox-enabled third-party apps available online, many may add some of this functionality for you. If you're a developer, you might even be able to add this functionality yourself. Visit our developers site for more information.