Yes its stille AppleScript. mail-to-evernote.applescript is the executed script in the automator workflow.
Hey, i created a fork of your workflow which ended in a complete rewrite (which i hope is okay with you). Besides the complete code rewrite, the note is tagged and a notification center toast confirmation is shown when done. Otherwise the workflow result is exactly the same. Attachment handling is in the works. You can find more information on the github page of mail-to-evernote. I am keen to read your feedback.