I found several posts on Tumblr regarding that dude. One of 'em listed several BG Stallions that had his color scheme, though not a one had his CutiHandsome Mark. Yeah, Comet Tail was the most popular guess, right next to Wisp.
Ya, I do too, but at the same time, I think it's silly that they think it's Soarin. Soarin is white, like you said, and his hair is darker. But I don't think it is REALLY stupid though. I wanted to see Soarin too. Some people even think he was Shinning Amor too! O_o WHY would they think that? Do they REALLY think Hasbro will do such a thing knowing that's Twi's brother!?