I hate gardening. But I've gone back through the comments and pruned out ones that substantially reduced the average comment quality. I really hope that I don't have to do this regularly; it would force me to move to WordPress more quickly than I'd otherwise like, or maybe use Disqus. I'd really prefer to be able to wait and see what the updates to Blogger have to offer when they're onstream. If your comments have been hit, use the ones that remain as models of what doesn't get pruned.