After trying to find out how to update the software, only to realize that it happens automatically, I discovered an easter egg hidden in the device.
If you go to Settings > Legal Info and scroll to the bottom. These messages will display:
The new Nest thermostat looks even better than the original. Would upgrade if I hadn’t bought my current unit just two months ago. Easter eggs are always fun to find. Good to see a development team with a sense of humor.