Well, yes and no. Gruber uses MT, which I remember has a special template for the feeds. WordPress, does not. In WordPress you have to edit a core file called
wp-rss2.php, a file that’ll easily be overwritten in an upgrade. In other words, having a template for the look of your feeds means upgrading will be easier.
Good idea? I think so. Apparently enough people think so too, that a patch has been made, which when applied will allow you to create custom feed templates right in your theme directory. As far as I can see, it’s an obsolete patch with newer versions of WordPress. Too bad it’s not already part of WordPress.