A third edition of Garner's Modern American Usage is apparently on the way. Saw this note on the bottom of his daily usage tip:
If you’re interested in serving on a panel of critical readers for the third edition of Garner’s Modern American Usage, please send your resume to email@example.com for consideration. This commitment would involve 10-20 hours of work before July 30, 2008. If you are chosen, appropriate attribution will appear in the third edition.