My first thought on seeing the title and hearing Sheev's laugh was that it was going to have some flashbacks to either Luke or Anakin, but then I remembered that there are already three movies for each of those characters. So, yeah, maybe it's Rey taking the name Skywalker as a mantle, or even just replacing the word 'Jedi' with 'Skywalker'. I'm not crazy about that, because it reminds me of the "Tell me another tale of The Shepard" nonsense they tried to pull in the Mass Effect 3 ending, but maybe if JJ handles it with a little more nuance than none at all he might be able to pull it off.
Or, hell, maybe the Skywalker in question is Kylo Ren, and he's going to have a revelation and start calling himself Skywalker to distance himself from his old ways (I've already seen people theorising that him Rock Bottom-ing that dude in the trailer is actually him killing one of his own knights while fighting for the Rebellion with his own defected Stormtroopers). Or it's Leia. Or Ghost Luke. Or Ghost Schmi. Or, like The Last Jedi, it's going to refer to multiple things throughout the movie. I don't know, but I'm looking forward to finding out.
EDIT - Also, we'll obviously have to see it in full, but I'm calling Rey as an early contender to win the coveted Best Flip award. We anime now, bois. Prequel flips ain't got nothing on that work of art. Given that it also looks like we're going to get some underwater Death Star 2 action, as seen in the early concept art books for the Sequel Trilogy, I wonder if they're also going to bring back the best idea in all Star Wars history: