In older versions, the Notification List entries were sorted alphabetically, and people
wanted them by date. Now they're by date, and people want them alphabetically!

Sorting for the list is handled in /lib/MT/App/CMS.pm, particularly around about lines 4455-4462 (in Movable Type 3.33), for the page.
CODE
if ($type eq 'notification') {
$app->add_breadcrumb($app->translate('Notification List'));
$param{nav_notifications} = 1;
#@data = sort { $a->{email} cmp $b->{email} } @data;
$param{object_type} = 'notification';
$param{object_type_plural} = $app->translate('email addresses');
$param{list_noncron} = 1;
}
You could try uncommenting the #@data line, but I suspect that this handles the sorting for a single "page view" on the list only (ie, the over list would still be sorted by date, but each page would be alphabetical). So, if you've got more than 20 (or however many rows you're showing on the page) entries on the list, I'm thinking you'd need to do further work on the code above that as well (ie, up in the lines 4300+).
Remember that code modifications are completely unsupported, so if you're going to try this, make sure you have backups, and are prepared for the possibility that it might all go horribly wrong.