Currently, the "You have new messages" is generated
only when a user's talk page is updated. It would be
cleaner if this message was generated whenever *any*
of the user's talk subpages was updated, too.
This would prevent vandalism on archived pages. It
would also allow users to more easily maintain more than
one user talk page if they desired. For example, one for
thank yous, one for older-but-ongoing discussions, and
one for general comments.