So much for leaks and rumors, it's somewhat official now, as shown in the attached picture, Sprint has updated it's online listing for the EVO LTE, stating the OS is now Android 4.1. Now with that being said, don't everybody get all crazy and start unrooting to get the OTA, just be patient and what for all the devs to get ahold of the OTA/RUU and start baking roms. If you unroot and accept an OTA you run the risk of getting updated software and losing the ability to root or gain s-off.
So the keyword here, is....PATIENCE!!