Motorola: Sprint customers should call our new phone the Moto Ex
It's possible that the reason for Sprint's decision to bypass the Moto X has to do with the original model's failure to support Sprint Spark. This is the tri-band LTE network used by Sprint to offer faster data speeds to customers. Spark requires a handset to be modified to work on the network. The technology added allows the phone to decide which of three LTE bands is best suited for a particular task.
Pre-orders for the Motorola Moto X started on Tuesday for AT&T customers.
source: @Motorola via GigaOm, AndroidandMe