Currently, no. There's also no way for:
- Users to edit comments once submitted (similar to how comments work on the main site)
- Users to up vote comments (similar to how comments work on the main site)
- Comments to be threaded (not going to happen, we don't do this on the main site either)
- Markdown to be used
I think what we need is some of our WP Wizards from Wordpress SE to come together and give Stack Exchange a better comment system delivered by a plugin. Why? I doubt it would be implemented any other way. If you even mention PHP at StackHQ people rush to you with tissue.
If something totally awesome was gift wrapped on Github, I'm sure some swag would go out to those involved. If Stack Exchange disagrees on the swag, I'll personally write thank you notes in crayon and send them out to those involved.