Basically I want the *Messages* buffer to always scroll to the bottom when a new message arrives.
Can I do that?
Here's an implementation that uses the new advice style.
(defun message-buffer-goto-end-of-buffer (&rest args)
(let* ((win (get-buffer-window "*Messages*"))
(buf (and win (window-buffer win))))
(and win (not (equal (current-buffer) buf))
(set-window-point
win (with-current-buffer buf (point-max))))))
(advice-add 'message :after 'message-buffer-goto-end-of-buffer)