Well folks, after learning that the unlock for iOS 4.2.1. should be available tomorrow, here’s some more good news from the homebrew community: you can now unlock a WP7 device even without using a Marketplace developer account. The process requires a USB cable and a couple of clicks, plus the executable found here.
If you get stuck or have issues with the process, you’ll find suggestions here. The minimum OS supported is Windows XP SP2 and since this is the first release, expect a bug or two. Created by the folks of ChevronWP7, the tool will sideload apps and already Microsoft has issued a statement about it.
As usual, they mention the voided warranty, disabled functionality, interruption of Windows Phone 7 services access and phone bricking. Well, actually you should beware of these factors when you decide to unlock the device, so proceed at your own risk.