What about Miles Morales,the Spider-Man of the Ultimate universe? Well he is on his way in to the regular Marvel universe as hinted in Cataclysm: The Ultimates' Last Stand #2
Comic readers know that the Ultimate universe is already in trouble, since the 616-universe Galactus came over at the end of Age of Ultron miniseries. Since then, he's merged with his Ultimate equivalent, the swarm of robot drones known as Gah Lak Tus, and is even deadlier than usual, and the rumors that Marvel could completely end the Ultimate line were rampant at this year's Comic Con.
So, with Miles Morales being the most popular character leaving the Ultimate universe this makes the rumours seem more concrete.