New Comment Editor
As many may have noticed there is a new comment editor today. This should solve many problems as well as make the commenting simpler. It uses markdown but you can use selected html interactively with your text/markdown and it will be interpreted.
Click on the gray "wmd" text in the right hand side of the icon box for details on the editor itself.
If you have any questions or problems just leave a comment on this discussion thread. This does allow for nested quoting and should fix the Opera problem not seeing the paragraph breaks without having to put in the br's. It should tidy up any other issues as well, such as using a mobile browser to add comments.
Also feel free to use this discussion topic as a place to try out the editor.