It's one thing to ship MVC & Silverlight as unsupported projects and iterate fast, but quite another to iterate phone software quickly where you could potential

It's one thing to ship MVC & Silverlight as unsupported projects and iterate fast, but quite another to iterate phone software quickly where you could potentially brick millions of phones with one small software update. As noted in this blog post, an update applied to the phone broke it and the user had to get a brand new phone. This added a customer service burden to the mobile provider / network - which in turn means they will moan to Microsoft when they do this and give them less enthuiasm for WP7 devices in future if it keeps happening.