Chris Walsh, part of the ChevronWP7 team and responsible for the current ChevronWP7.Updater app, which used Microsoft's own tools to push NoDo to thousands of Windows Phones prematurely, has blogged about why he pulled the app.



From WP Central:

On Monday, I released a homebrew utility that attempted to install unreleased updates to Windows Phone devices. The tool successfully passed my own tests involving multiple update scenarios.
I was later informed by Microsoft that there were several problems with my tool and the manner in which it changes phones.
Despite the fact that all outward signs indicate the phone has been updated to build 7390, Microsoft tells me otherwise. Part of the problem, the company says, is that I incorrectly used an undocumented API to deliver updates.
Most problematic, Microsoft tells me that updating in this manner will place devices in a "non-serviceable state". In its blog post describing the situation, Microsoft instead says devices updated in this manner "may" no longer receive updates

  Walsh speaks on ChevronWP7.Updater and breaking phones