Why is there a file size limit?+discussion
File storage on full-fledged servers isn't nearly as cheap as file storage on something like Amazon's S3 service. I might look there for large files.
We may also add a configuration option to use S3 with wagn, but that would mean sacrificing file security (other than security through obscurity, which is pretty flawed)
So you'd separate the site server from the media server, basically.