Several Directives take ikiwiki-formatted text as arguments,
such as the then and else arguments of the new if directive, or the
desc argument of the shortcut directive. However, smileys do not work in
these arguments.
Since the arguments to Directives might use the same syntax as smileys for a different meaning, smiley substitution should not happen until after Directives.
Sorry, I should have filed this under bugs, not todo.
Also, for an example of this issue, consider the sample conditional on conditional.