Some sad, but expected news on the homebrew front: the Chevron Labs unlock, the only Microsoft-sponsored "jailbreak" for Windows Phone, has now officially expired. Chevron Labs' Rafael Rivera posted on the group's blog that, as of August 11, any unlocked phone will be once again locked the next time that device is synced using the Zune desktop software.
The change, which was announced back in April, will not affect any Windows Phone devices that are unlocked using other methods. It may, however, affect those who moved to a paid App Hub account. If you are one of those people, you may have to use the Developer Registration tool to unlock your phone once again. Instructions can be found here.
The Chevron Labs project was shut down for a few reasons, technical, logistical and ideological. A big part was because most people who unlocked their devices never went on to publish apps, which was the Microsoft's primary goal in the effort. For a lot of us, the motivation behind unlocking our phones was not to test apps we developed, but rather to be able to sideload apps and tweaks that would add functionality that was not inherent in Windows Phone 7.
If there is a bright side, it is that the former ChevronWP7 members: Rafael Rivera, Long Zheng and Chris Walsh will continue tinkering around:
"Fear not, we will continue to explore other ideas with Microsoft. All sides are still very interested in the hobbyist and homebrew developer communities."
Source: ChevronWP7
