Think it's a good bet that the OT story line will have been referenced here, to give...
Siblings separated in early years, and refinding their identities
Those identities leading to links to key characters from OT ( Han, Leia, Luke)
Possible sibling differing paths ( good/evil) Kylo Ren searching for Sith/ jedi artefacts linked to Vader ( "Kylo I am yor grandfather ":lol: )
Lukes bespin saber initially being the draw for main characters ( searching for it...bad guys, protecting it...good guys)
Luke doing a Yoda on a planet where he is contemplating his mistakes, culpability for something disastrous involving jedi ( academy destruction?) and being found towards the end of TFA, setting up the next instalment.
Conjecture and supposition is rife, we can all let our imaginations run riot, in the end it doesn't really matter.....we are all getting a chance to watch a new film which is awesome 8) and we will watch the start, the music will kick in, hairs will stand up on tha back of our necks and....Bingo " Star Wars Fans.....we're home!" 8) 8) 8)