I don't see what the big deal is, all I see is a guy in a dress, and this certainly isn't the first ad to do this, I remember an ad in one of the video game magazines many years ago that had a guy in a pink tutu, he looked absolutely rediculous in it by the way, but hey whatever, don't see anything in this Sprint ad hinting at transgender people. Some people are just way too insecure, offended too easily by the littlest things.
My appologies to the above post (had what I said above already typed out when you posted), but just my feelings on the matter, that it don't matter, not to me anyway. I'm not a guy in a dress, at least I don't feel that way, and if somehow anyone else thought differently about what I look like in a dress, so be it, doesn't bother me one bit.