Some comments are written in very bad format (leetspeak, all lowercase, bad grammar, etc.). Thus it takes quiet a lot of time to understand what a man that posted a comment wanted to say.
I think such comments shouldn't be left in this state. I think it would be good to have the possibility to edit and clean them up. What should be done with comments posted by other users if they have some value but are badly written? Should there be possibility to edit them? Should I flag them for moderator attention? Should there be review system similar to the current one for questions and answers?