It would be nice to have a better default description that will show up on Google authenticator. Currently it is 'WordPress blog', but if you have more than one WordPress login that is no use. The WordPress.com version automatically gives '[url]: [username]', e.g. 'blogs.com: joe' as the description.
I think its quite a simple fix on line 241 of google-authenticator.php:
$GA_description = __( 'WordPressBlog', 'google-authenticator' );