There's a brand-spanking-new, baby-powder-blue edition of the Chicago Manual of Style, hitting the shelves (and the webs) by the end of this month. My inner citationologist is a-quiver from footnote to header. Word on the street is that the CMS is encrusted with jewels no less coruscating than this, for the quoters-of-blogs: "There is no need to add pseud. after an apparently fictitious name of a commenter; if known, the identity can be given in the text or in the citation (in square brackets)."
MLA and Harvard, eat my shorts.