Whenever people find out about leaked products or demos, many want to jump right on it. That's exactly the case with the New Xbox Experience. But it turns out installing the leaked files will lock you out of Live until the NXE is set to be released!
Many that have downloaded the leaked version of the NXE, have found themselves completely locked out of Xbox Live. And since the release date for the new experience is set for November 19th, you're looking at about three weeks of lock down. That's a long time to go without Live!
So take all of this as a word of warning. Don't install the new leak unless you're okay with not being able to access Xbox Live for the next couple of weeks and you're willing to run the risk of being banned by Microsoft. Of course, there's been no word about bans yet, but it is always a possibility.