The new Nikon US instant rebates for September are now live and include 30 different lenses, 2 Speedlights and 2 teleconverters (only 8 lenses and 2 flashes were available in previous months). Nikon basically doesn't have any new products and is trying to generate additional revenue by aggressive promotions. In order to qualify, you still have to purchase one of the nine current Nikon DSLR cameras. The rebates are stackable which means that you can buy multiple lenses with one body and still qualify for the savings. If you get few of the high-end lenses, the camera will basically come for free (depending on the model):
For a full list of qualifying products, check this link. The rebates will expire on September 28th.
Rebates from other manifacturers: