i think the legend of how Reshiram and Zekrom were once one pokemon might be a hint at a future game. Theres the main story line right there.
Evil guy: I will reunite the two legendary dragons to form the ultimate Blue Eyes White Dragon ... I-I mean Reshirom/Zekram.
Our character: ... (Why is this all we ever get to say? Granted there are a few choices where we can chose a yes or no response, but still)
Evil Guy, Sucess! You failed to stop me now i will tell you how to defeat me. go catch Kyurem (i will also be so kind as to tell you where he is and how to get to him) change his form and then come beat me, I will patiently wait for you.
Our Guy: ...
Evil Guy: You listened to what i said and you beat me! How is this Possible!
Our Guy: ...
Evil Guy: i had a magical change of heart and now i realize that my life's ambition was wrong, thank you 14 year old stranger!
Our Guy: ...
the end.
See, the story practically rights itself. As for N, i think he might be like Red and be the strongest trainer to beat in EarthRuby/OceanSapphire (just my thoughts on the remake titles). I also feel like this was the biggest unresolved part of the story. Gheists gives you the Adamant orb, Lustrious orb, and Griecious orb at the end of the game then runs away, but they never say what the orbs are for (b/c Dialga, Palkia, and giritina arent even in this game so why bother give the orbs?) and they just leave it at that. I think it might have something to do with Kyurem's alternate form or the combination of Reshiram and Zekrom. we will see soon enough though