One of the larger concerns we've heard regarding Windows Phone 7 is its relatively closed nature, sending shivers -- or sounding a battle cry -- through the likes of XDA Developers and other hacking sites. And it looks like the call to arms has been answered, as the Zune firmware has been cracked open, paving the way for sideloading apps outside of the Zune Marketplace. As the heroes put it, "the limitations of XNA are now no limitations at all."

Here's to hoping we see some killer apps in the near future, and later on Windows Phone 7. [Zuneboards via Engadget]