I noticed this too last week and almost pulled the trigger. It's back up to $1,121 now. I'm torn between this and waiting for the 2013 Google TV model.
If you're waiting for 2013, then consider the Sony line. The reason I discounted them before the 2013 models is because they were staunchly active-3D, and I really am a fan of passive, and Sony has finally caved and accepted that passive is what the public wants.
But be aware: the 2013 prices are going to be horrible for all manufacturers for several months. Go to camelcamelcamel.com if you want to see a historical snapshot of the 47LM8600 and other products. Many of them start in April at outrageous pricing before coming down to earth.
Grow milkweed. The Monarch Butterfly requires it, and its numbers are dwindling fast.
Adorama listed the 2013 55LA7400 for about 2000. Adorama is usually more expensive than Amazon, so I would expect Amazon to sell 55LA7400 for about 1500.
Also, Toshiba 58L7300U seems very promising. BH Photo Video lists it for 1699. Amazon would probably sell it for 1300-1500. This model is a good value proposition for me because I never watch 3D, and it is 3 inches larger than 55 inch models.