The Force Awakens definitely feels like a follow up to the OT, I love the look of everything! I wonder what approach Disney will take with the opening scroll? A long time ago in a galaxy far, far away or In a Galaxy far, far away. Here are my thoughts on what we have seen and where it could go. I haven't read any pages back so I apologize if anything is repeated.
Rey: Definitely the heroin of the new saga. At first I thought she and Luke have been working together finding force sensitive beings and that her staff was a spear sabre (sabre on just one end) or double short bladed sabre. After the new trailer I think she not only doesn't know Luke but isn't force trained at all and gets involved in the new struggle while on one of her scavenger runs. Perhaps she comes across BB-88 who is in possession of Anakins sabre or gets involved when she comes across Finn who crash lands on Jakku. She and Finn both looked surprised when Han relates that the stories of the Jedi/Sith/Force are all true that tells me they aren't trained or even thought it was possible to do such things.
Finn: I think hes the new Han he may be force sensitive but I think not. He just has the sabre because he and Ray are on a "mission" to return it to a Skywalker heir. When he confronts Ren in the woods he just uses it to defend himself.
Kylo: I think Kylo and the Knights of Ren are a group of Force sensitives who emulate Vader and have been gathered by the new "Emperor" character and Kylo wants to take it to the next level and gets involved with the First Order who give him new resources to finish what Vader started but we don't know what Kylo believes that to be. Does he mean exterminate all Jedi/force users or turn Luke to the Dark Side or Bring balance to the force or something entirely new we don't know what he believes based on what hes been told or discovered for himself.
Luke: I don't know what to think about Luke yet, is he training Jedi or has he completely abandoned that thought and just kept the Force within himself to maintain balance and to prevent the resurgence of the Dark side. There is some reason why he is being kept completely secret. The leaked concept art that showed the burnt Vader helm was being held by the new bad guy who also had a robotic right hand very similar to the hand of the cloaked figure touching R2 in the trailer. Could Luke in fact be the new "Emperor" or is he using the Knights or Ren to gather and destroy the relics of the Sith and Kylo falls to the dark side and decides to continue in Vaders path. The only thing I fear is there will be a moment where Luke comes in to save the heroes and is already a force ghost and that is why he hasn't been shown.