Two features I really think should exist to push WinSnap over the top would be:

1. Allow a more customized email feature, where, instead of simply starting up the default email client with the most recent capture attached, you can setup a default email address it will send to in the background, after you enter in your own email parameters to send from.

3. FTP capabilities -- enter an FTP address with username and password and WinSnap will auto upload the most recent capture to that location.

Otherwise, great product.

You can always create a new "command" under Tools -> Customize to run a ftp/scp client.