And google is going to announce its new phones on 4th oct. If they are still 16gb then you have a point. With the new android update system where the phone has 2 system partitions and load the updated version on rebooting the phone means they will need more space anyway.
2GB is more than enough for a system partition. You can fit two into a 16GB phone. The only real consideration is app and media size, and google's historically been on the low end of that.
