Yes, I cobbled together a plugin to deal with this:
http://codex.wordpress.org/User:Kafkaesqui/Projects#Break_Text
mdawaffe is correct in that the forum post about it was wiped (I'm seeing a lot of this...), so here's a brief explanation of use:
Install plugin, activate it, and in wp-comments.php, replace
<?php comment_text(); ?>
with
<?php break_text(comment_text); ?>
The parameters are:
<?php break_text(func, 'args', cols, 'cut'); ?>
func -> WP function name - this is the function name break_text() replaces, without all the php syntax. In this case, comment_text.
args -> Parameter(s) passed to the WP function.
cols -> Number of columns or characters to break a line of text at. Defaults to 60.
cut -> Character(s) to use for the break. Defaults to a space.
Another example is:
<?php break_text(comment_text, '', 72, '- '); ?>