Being that these units won't be available for some time, this question may seem premature but I thought I'd throw it out there anyway so as details come in, maybe light could be shed upon it. The preliminary details for these newer models indicate that they will include a mobile hotspot built into the phone. I'm wondering if these built in mobile hotspots will be 4G only or backward compatible to 3G as well since it will be at least two years before 4G covers the entire 3G map. I see that Verizon has released the 4G MiFi box today but wondered if I should hold off on that since these phones will have that feature built in. I know they'll charge separate for it but it beats carrying around two devices.