K - I've got it and installed it. 1st - a few things I learned that I would have done differently. Buy it on amazon. It would have been free shipping (free 2 day if you have prime). Could have saved some $$ that way. Didn't know it was for sale there until after I ordered.
Anyway, install was a breeze. Be sure to take a picture of your wiring before you remove the old thermostat in case there is any confusion about wiring. Anyway, I had the old one removed and the new one installed in about 20 minutes. Nest comes with all the screws, mounting plates, and even a nice little screw driver that did the job quite well.
Setup was also a breeze. It boots up for the 1st time and then runs through its setup. It auto scans for your wifi network, you put your password in, and it immediately updates itself. Once that is done, you continue setup. It's all pretty slick.
So, now its monitoring my patterns for when I turn the air or heat up or down. I've also added a few baseline things like to turn the ac off when I leave for work until it reaches X degrees and to then bring it back down to X degrees when I get home. We'll see how that goes tomorrow.
The web and iphone interface/app work great. What you see in the browser version is pretty much identical to what you see in the app. So, decent info is avaiable. As it finishes doing some baseline stuff, it gives you a pop up on the Nest itself. For instance, I just noticed a pop up indicating that airwave is now enabled (their tech for turning off the air for a bit and just running the fan to circulate to the cold air (eg cost savings concept).
Anyway, that's all I have to say for now. If you have any questions, ask away; otherwise, I'll post in a few days with any additional feedback. So far, I like it.