I know that AT&T will have the same phone number, so no need to have a separate number for its Gear S 3G (and reportedly LG 2nd Edition 3G), how about TMobile's? I had the Gear S, and it was a pain to have 2 numbers.
T-Mobile is also working on allowing you to have one phone number being used on multiple devices... this is going to be an awesome option once it is launched..