Hey - GREAT PLUGIN Marcu5! I was thinking about making a plugin like this to handle my comment replies and then found yours. It's very close to what I ultimately want.
The only problem I had with it that I had to fix manually was the use of WP_PLUGIN_URL as a constant - for some reason the image was always "broken" - and I don't know enough about WP coding to know if this is a problem with my blog and how it handles URLs or a bug in the code. But the image tag always had WP_PLUGIN_URL as part of the image URL, and that didn't seem right to me.
Anyway, my suggestion to your plugin is to have the ability to style the text that's inserted. Your plugin is hard-coded to do @Author with a link to their comment.
Before your plugin, I've been hand-coding the following HTML on a lot of my comment replies:
<b><a href="theirblogifsubmitted">Author's name</a></b> - my comment response here
So I would like it if the plugin let the user set up stuff with variables. I'm fixing this (minus the a href part) by manually changing the code in the plugin's php. You're already pulling author from the comment, so maybe it wouldn't be too hard to pull their URL as well.
Then the user would, in the options, specify their comment blog. For example
<b><a href="$url">$author</a></b> -
I have other suggestions as well (such as direct email replies and possible "auto-fill" of this information into the comment field when admin is logged in, looking at a post with no admin replies, so that bulk-style comments are faster) but I'll refine my thoughts on the matter and submit when appropriate.
thanx again for a great plugin!