"On a similar note, we're aware the ChevronWP7 unlocking tool is still being utilized since it has been discontinued," according to the ChevronWP7 team. "Although this has been subtly communicated before, we'd like to reiterate Microsoft has informed us the 'coding error' used in the ChevronWP7 unlocker will no longer work after the next Windows Phone 7 update (officially announced at CES 2011). We hope to provide an update after the discussions."
ChevronWP7 was discontinued less than a week after its release about two months ago. ChevronWP7's three developers, Long Zheng, Rafael Rivera, and Chris Walsh were approached by Brandon Watson, Director of Developer Experience for Windows Phone 7, and decided to kill their app.
Zheng, Rivera, and Walsh have said Microsoft wants them to become more involved with the shaping of the homebrew scene on the Windows Phone platform, but ChevronWP7 will not be the way to do so. In fact, the trio has a meeting with Microsoft's Windows Phone 7 team next week in Redmond, and they will be focusing on homebrew as well as stronger protection of WP7 developer intellectual property.