It appears that there is an internet-wide sale going on today. Right now you can pick up a Nest Learning Thermostat for around $199 at the Google Store, Amazon, Best Buy, B&H Photo, Target, and even Ace Hardware. That's a savings of $50 off the normal price of $249. The Google Store made a post today on Google+ about it, and from the image, this promotion should be running through July 8th.
This deal is incredibly widespread. It looks like basically anywhere you can buy a Nest, you can get it for $50 off. So if you've been considering one, the convenience of picking one up in this sale at your preferred retailer might be enough to push you over.
At $199 this deal is tied for the best price we've ever seen. Should you be waiting for a discount before you pick one up, this might be as low as things will go for a while.