If you’re thinking about signing up for a carrier-subsidized Samsung Galaxy S4 here’s a bit of good news: XDA Recognized Developer Djrbliss posted a rooting guide that is dead simple and works with all variations that use a Qualcomm processor (AT&T, T-Mobile, Verizon, etc.). The technique was originally developed for Motorola devices, and thus is called Motochopper. It will work for Windows, Linux, or OSX. Windows users will need to have the latest Samsung USB drivers. With that prerequisite satisfied, you need only run the .bat (Windows) or .sh (the other OSes) file get your root on.
This was just released yesterday, and there are a few things to consider before giving it a spin. Rooting the S4 can be considered a bit risky because there isn’t a clear path for fixing the device if rooting fails. But I image it won’t be too long before someone is able to dump a stock image and get a custom recovery working on the device. And I’m sure you’ve heard the news that at least some carriers will be delivering phones with locked bootloaders (booo!) but that’s never stopped us before. Maybe the same exploit that worked with the Atrix HD will work with these since the processors are cousins?
If you still want to throw caution to the wind, head over to the original thread for a download link and instructions.