Seems like the employee training for the HTC One XL on AT&T has begun yesterday and we may have more information on the release date now.
This document was leaked over on xda-developers by EGBTMagus and he also leaked a photo showing the EOL for the Inspire 4G.
From the leaked document we can tell the Inspire 4G will be discontinued on April 22nd and that would make for the perfect time to restock shelves with newer devices and release a new device.
EGBTMagus, XDA Member, was told by an HTC Rep that the HTC Vivid would replace the Inspire 4G spot and at it’s price point and the HTC One XL would replace the Vivid at it’s price point. It all makes sense and points to the April 22nd release date, especially since the employees are testing it now. Take that with a grain of salt though as this is all just rumors and speculation of course.