The very first time I saw the opening, that exact thought occurred to me (and I unfortunately ended up getting my hopes up...). The imagery of Satoshi and Pikachu alone walking into the distance leaving glowing footsteps behind, and the kid literally stepping into them, does lend something to that idea. But now I don't really think so. I'm thinking that if the anime did want to reveal a new main character for a future series, they wouldn't give him a Pokémon tied to a previous generation. ORAS is only going to be relevant as long as Gen. 6 is. Nor do I think he'd pop up now, when XY is only into its second year, and Satoshi still has five (soon to be four) badges left to earn.
I do like that there's going to be a character tied to Satoshi and, whether or not he ends up being a rival or just a new trainer trying to learn from him, I hope XY can use him to make Satoshi's journey more interesting. He desperately needs something to do other than challenge Gym Leaders. It'd also be nice if the fact that he has a Kimori could be hinting at a certain other Pokémon that's a part of that evolutionary line, that Satoshi just so happens to have back at Ookido's lab...