One thought I had about the submission process stems from being a guide author for GameFAQs.com. There, they have a public FTP server that has write capabilities, but not read or rewrite. One way I could see helping the submission process would be to open a similar system, allowing the author the ability to create a subdirectory with their name, upload the file, and (with the read/rewrite block) still not allow distribution of unaccepted plug-ins, or the alteration of plug-ins currently under review. This would eliminate the possibility of losing files to e-mail errors and give the author the peace of mind that the file definitely made it since they can see it on the destination end of the FTP client.
Just the thoughts of a new user...