All of my iPhone-owning friends jumped ship when the first Motorola Droid phone came out at Verizon. Their reason: A more solid phone on a more free platform. The fact that Verizon offers the better coverage was just a bonus to them and icing on the cake.
It will all continue to ensure that the Android platform overtakes and remains high on the list, unless Apple can stop their iron-fist rule.
Point 2: Pretty much the same as point 1. The users are opting for the Android devices because of not only the openness of the platform, but also the fact that it is cheaper overall to have a plan for a better device running under a better OS.
Point 3: Exactly! The people who sought out Android devices will continue to upgrade to newer and newer Android-based options!
Point 4: I live with 2 T-Mobile subscribers who tell me otherwise. They tell me how they hate the lockdown of the iPhone by Apple. I mean, really? You band a calendar app and remove it remotely from user's devices because it has semi-nude pictures? Go freedom!
However, Apple decided to lock themselves into ATT for the carrier. That forced Verizon to toss its weight behind Android and alternative device makers and this has proven to be a MASSIVE hit to not only ATT, but the Apple iPhone as well. To think otherwise just seems crazy.