In 2014, Lucasfilm/Disney officially 'wiped the slate clean' of the original Star Wars Expanded Universe, which for years was sort of the official continuation or expansion of the original six Star Wars films. There were rumors that they would do this anyway-When the sequel trilogy was announced, it was stated to be an entirely original story, and for years, The Clone Wars series-which remains canon-had made changes to some EU lore, such as the history of Mandalore (Where Jango and Boba's armor design come from), the certain personas and lives of 'background' Jedi etc. The original EU is of course mostly still available, although re-branded as "Legends", much as how works of non-canon were labeled "Infinities" back in the day.


I think I'll start with the core OT characters, and if this thread is sucessful maybe add a bit more observations, about the new characters as well (Especially Kylo Ren and his counterpart of sorts, Jacen Solo).


Luke-In both continuities, Luke eventually starts to rebuild the Jedi Order, first on Yavin and later in their historical HQ of Coruscant. He's pretty much sucessful, restoring it to at least some aspect of it's glory before the Empire, although with some changes (Jedi can now marry for instance).

Despite the chaos of the Yuzzhan Vong War in "The New Jedi Order Luke is able to settle down and start a family with former enemy Mara Jade, although his wife is killed off when nephew Jacen Solo goes bad. Both versions of Luke eventually go into exile, but while the exile of Luke in TFA appears to be something he chose to do himself, Luke is sort of forced to leave by the corrupt ruler of the Republic, Daala, for not stopping his nephew in the first place (He eventually returns of course). I

n both cases, it appears Luke sort of uses the exile in part to search for lost Jedi or force lore, in TFA's case the first Jedi Temple, and in Legends case more mysterious force cults.

Although Luke does lose several Jedi allies during the wars that follow the OT, his order remains pretty stable until the events of the Legacy series nearly a century later when Luke is dead, where it is pretty much wiped out again by a new Sith Order allied with a branch of the Empire, whereas his Order in the new continuity seems to be pretty much decimated almost right away.


HAN-Han does remain with the military for a bit following the events of ROTJ. Although he resigns from a formal position, he doesn't return to his smuggler's life, although his, Chewie, and Lando's old smuggler connections prove valuable to many plotlines in the books. He sticks with Leia and the rest of his family, even despite the tragedy of not only losing Chewbacca, but eventually both his sons (Although he does suffer a bit from depression after Chewie's death). Han in the novels seems to eventually totally give up on Jacen's redemption (although he's still sad) while TFA's Han still believes somewhat to the very end.


LEIA-The backstory for the new post-ROTJ EU emplies that like her counterpart in the Legends continuity, Leia did eventually return to politics, but eventually grew tired of all the crap and retired. In "Legends", she uses the opportunity to finish her Jedi training and become a full-fledged Jedi by the time of the "Dark Nest" trilogy pretty much. In TFA's backstory she however instead forms the Resistance, assuming a military role similar to her rebellion days. Like Han, she loses her sons but finds strength with her daughter who becomes a powerful Jedi.

CHEWBACCA-In both versions, Chewie remains the loyal buddy of Han Solo, and a sort of uncle to his sons and daughter. However, in the early NJO, Chewbacca is killed, while of course in the new movie Han is killed. Han takes some time to get over Chewie's death, while Chewie, while clearly in mourning, seems to quickly accept Rey becoming the new "Captain" and helping to find Luke.

THE REBELLION/THE REPUBLIC-In both cases, the Rebellion eventually becomes a New Republic, although the Legends one settles on the historical capital of Coruscant, while the one on TFA is based on another (although somewhat similar looking) planet. It's unclear how much Starkiller crippled the Republic, maybe we'll see later on. In the books, during the NJO, the Republic is eventually reorganized into the Galactic Alliance, although it eventually falls to a new version of the Empire....


THE EMPIRE-Like in "Legends", the backstory materials from "TFA" seem to indicate that after so many defeats, what's left of the Empire sues for peace and to be left alone. In the original EU, this makes this a somewhat more benevolent entity, without the influence of Palpatine and under more cool-headed leaders, they eventually become more allied-through not only treaties but by blood (The Fel Dynasty being a mix of Solo/Antilles/Fel lineage-it's complicated!). However, much later, a Sith faction led by Darth Krayt (A Vong-warped Clone Wars Jedi raised by Sand People), topples the Jedi and takes over the remnant, recapturing Coruscant. This actually creates two Empires-one, the Fel Empire-is more like the 'nice' Empire, while the Sith faction of course is pretty much a new version of Palpatine's. This happens mainly in the Legacy series.
The First Order of course seems to form far more quickly, and mostly builds up in secret while the Republic believes the Imperial remnant is no longer a threat.