By popular demand, comments are now editable!
After entering a comment, you'll see an Edit button. Clicking the button will load the comment into the comment text field, after which you can Save it again. The edit date will be listed at the bottom of the comment.
While touching this, I went ahead and added edit dates for blog posts also...so from here on out, if you edit a blog post, both the post creation date and the edit date will be shown.
Just to prove this works, I shall edit this post!