Josh...wish I had noticed this thread sometime ago! (Would have saved some time...)
Anyway, might add that in the same language file admins can change the SUBJECT of the welcome email, from "Your password for..." (followed by the name of the board) (field name: PASS_SUB) to whatever they wish...useful on boards where most users enter a password on the new user screen, and where this message is used mostly for conveying other info!

Tony