Jon, I'd like to submit a feature request:
In WP3, there's an option to dismiss an update notification. For example, a plugin author may release a buggy update (say, 1.7.2), you test it, fail it, and roll back to the old version (1.7.1). Then you can tell WP to dismiss version 1.7.2 notifications. You'll start getting notifications again come version 1.7.3.
check out wp-admin/update-core.php:
$dismissed = get_core_updates( array( 'dismissed' => true, 'available' => false ) );
I'd request that your awesome notifier respect this setting, so I don't get updates every day for updates I already decided against. If this update is made, I plan to use this plugin on all my multiple WP sites.