In the light of recent events, here is an interesting story. Seems M$ is a bit more relaxed these days when it comes to hacking their products.
I can confirm that the jailbreak ChewronWP7 released works as I've tried it to install a NES emulator, and was able to unlock my windows phone 7 with no issues... The phone does lock back after a few days tho, as its designed to check with Microsoft servers periodically and erase the unlock.
http://www.engadget.com/2011/01/18/visualized-the-glamorous-lifestyles-of-wp7-jailbreakers/
To be a jailbreaker means different things depending on the device that you're busy hacking preinstalled walls from. If you're fiddling with consoles, a legal team would come highly recommended, but if you're tweaking mobile code, at least Windows Phone mobile code, you're in for a much sweeter ride. The ChevronWP7 guys that brought us the first jailbreak of Microsoft's Windows Phone 7 are currently in Redmond having a sitdown and a frank exchange of views with WP7 dev experience director Brandon Watson, and the amicable nature of their discourse has been evidenced by the image above. Microsoft is clearly taking a light-hearted and community-friendly approach to handling the (now inevitable) efforts at disabling limitations to its software and we can only congratulate its mobile team for doing so.
