The Watcher is my best guess for who can warn Earth. With the massive success of Fox's claim over their Marvel characters, and the FF reboot coming up, I doubt we will see Surfer returned to Marvel for a loooong time. Too bad, cause even though kind of a backround character, Surfer has a pretty big part near the end of the conflict with Thanos. Either way, he wont be in the Infinite Gauntlet storyline for sure. With the movies Marvel has slated, I just cant see it happening.