We all know Kyurem will be the main legendary (unless they introduce a new one... My opinion because in an interview with Junichi Musadi, he said he wants to make it like generation 1. So MAYBE, they will introduce a new Pokemon) So if Kyurem is, he will probably get a new form.
Second, We know nothing what-so-ever about "N" All we know is that he's the king of Team Plasma. We know nothing about his past or anything. And [shadow=red,left]HOW[/shadow] will Team Plasma actually seperate humans and Pokemon??? Other teams had the same goal, but they didnt have the Knoweladgeable plan to where it would work, maybe they could combine the powers of ram/rom To create Plasma to destroy humans so Pokemon can live freely??? Or they would use Kyurem to try and create a cold world to punish humans for what Team Plasma thinks capturing Pokemon is abuse?? It'll soon be revealed, the announcement for the third version should come May of 2012, i know thats far away, but itll get here, then maybe we will know the plot of the third version.