You can now attach up to 20mb files to Gmail messages, that’s up from 10mb. There was a time when a number of services developed that enabled the sending of large files over email, I would imagine their oxygen just got sucked out. To be fair, there are a couple that have developed much richer capabilities than simply sending large file attachments, like YouSendIt.
I have always liked YouSendIt for being drop dead simple to use and later for having some nice features, like the dropbox functionality for business users. The management of electronic documents continues to offer rich opportunities for startups.