Can you believe it? Today, 16 April, is the 50th birthday of Strunk & White. They've put out a very fancy Anniversary Edition in honor of the occasion. Now, the edition I have (and anyone reading this, and any writer in North America - at least - and frankly everyone else in the world SHOULD have an edition) is the Third Edition. My understanding is that the additions to the new one are nice enough, but the reviews seem to indicate that it's not enough change to go nuts to get the new one.
One thing that IS in the new edition (I heard this on NPR) is Dorothy Parker's quote regarding Elements of Style, as follows:
"If you have any young friends who aspire to become writers, the second greatest favor you can do them is to present them with copies of The Elements of Style. The first greatest, of course, is to shoot them now, while they're happy." -- Dorothy Parker, Esquire