My gathering's of Ornn info
Based on the song, notes, and a bit of what has been said here on the boards.
He is a Vanguard mostly made with Top Lane in mind. He is BIG and is at least from the time of The 3 Sisters. The people consider him and whoever his siblings are as Gods. The song seems to indicate that he created the Howling Abyss and he lives on whichever side of the bridge has a Mountain. He possibly uses Volcanoes as his forges and among his materials are Meteorites. (Sokka from Avatar should visit him and get a new space sword.) With "Mountainsmith" as his title, "The Shaping Hand" could be the name of one of his abilities or his passive. He loves spicy cherries. Part of his lore involves Anivia and something is her fault. He is probably taking to the rift to put an end to the civil war. He currently has no connection to Malphite.
Anything else? I think his kit will have him make terrain and possibly be heavy on locking down enemies.