Not only that, but also for a Linux user, you can already build such a system yourself quite trivially by getting an FTP account, mounting it locally with curlftpfs, and then using SVN or CVS on the mounted filesystem.
90% of people misunderstand that comment entirely. It was about the value proposition of Dropbox as of early 2007 (and also about the specific announcement!) and their long-term profitability, if anything.
They won't last.