Let the hive mind of Engadget get that for you.
"I am looking for a device that will stream sound from one source to several recipients. For example, I want to stream sound from my TV or stereo to my phone or MP3 player that has radio and Bluetooth capabilities. I have looked into radio transmitters and they seem like a decent choice, but I can't find one that uses external power (USB or from the plug) and I would want one with a transmit range of around 50 meters. Thanks!"
Yes, the number that was given is the 722s. Note the 's' - it is a different unit than the standard 722. Same with the 722k, also disclosed today - not the same as the 722 - nor the 722s.
Dish may change the numbers/names before the final release, or maybe they're looking to make a 722 'family' with variants.