The W Hotel Store 40% discount appears to be back with code WX4T7. I don’t know the expiration.
This offer comes up frequently (see for instance here, here, here, here, and here) but I haven’t seen it in awhile. Every time it pops up it’s worth noting because it really is a great deal, I bought my W Hotel bed (plush top with featherbed) in March of 2007 and I’ve been happy as can be.
40% off makes the price reasonable, shipping is free and they’ll remove your old bed for free as well. And the discount applies to bedding as well, though I personally didn’t choose mine from the W Hotel Store.
If you want automatic notification of the next time this deal pops up you might want to subscribe to this Flyertalk thread for updates.