Aspiring new iPhone 5 customers aren't the only ones T-Mobile is looking to please today. Hours after opening the pre-order period for iPhone 5 plans in the US, T-Mobile also quietly released a carrier update to bring LTE to all of its iPhone customers running iOS version 6 and above. The new update also gives customers visual voicemail, promises improved battery life thanks to better optimization with T-Mobile's network, and access to the FCC's commercial mobile alert system for public emergency notifications. Perhaps most importantly, it extends T-Mobile's new LTE network to unlocked iPhone 5s, too. But you may have more difficulty if you have a jailbroken iPhone: the company's update specifically says they aren't allowed, and that phones must be "officially unlocked" by a carrier or retailer.

Fourth-place US wireless carrier T-Mobile has been positioning itself as the industry insurgent lately, in March announcing it would replace the standard two-year contracts with a month-to-month offering. But even that plan doesn't offer unlocked phones, so there's potential for this update to pull unlocked iPhone users away from rival carriers. That outcome would certainly be music to CEO John "stop-the-carrier-bullshit" Legere's ears.