Bundled with hardware like the Wii console, Wii remotes, and Wii Play (which of course comes bundled with a free Wiimote) shipping to retailers on October 2nd, the Wii Remote Jacket should be available with those products as early as October 15th. Already got a Wii with an armada of Wii Remote missiles that need cushioning? Go to nintendo.com, or call 1-866-431-8367 to place your order (note: you can order 'em now, but the free sleeves won't ship until the week of October 15). Just punch in your console's serial number (what, you don't know it by heart?) and order up to four sleeves for your Wiimote collection.
Update: Many of you are getting errors when trying to submit your serial number. We think it best if you hold off a couple hours (maybe even a day or so!) and let the site get on its feet before hammering away at it. Let us know when your transaction goes through!