If we are talking about the evident problem of making mistakes in spelling, would it be feasible to put a spell check function into the commenting system @keithcollantine?
And it would be lovely if the @ mentions could be checked against existing user accounts, but I guess that is something that would bog down the site quite a bit.
I know that moment full of shame, when seeing how you leave a stupid spelling mistake in a comment and not being able to do much about it. But I am not that much of a fan of comment editing in wide discussion.