Man, this is hard work! To come up with all of the names and crap. Anyways, here's what I'm working with and a lot of the new names are placeholders until something better comes along.
There are returing characters, semi-returning characters, and new characters. Also, some of the characters get more definition in the actual story description than they do here in the character description. The reasons for that should be obvious.
Okay, no more stalling:
Returning Characters
Anakin "Nik" Skywalker - (25ish at mE1 start) The young pilot who becomes a hero who becomes a Jedi Knight, who becomes a double agent, who's not sure what's right anymore, who falls and becomes the Dark Lord of the Sith.
Obi-Wan "Ben" Kenobi - (35ish at mE1 start) The Captain who becomes a Major who becomes a Commander who becomes a General who wins a war, but loses his friend.
Bail Organa - The future "King" of Alderaan, he is now a Senator and a Prince.
C-3PO - A protocol droid serving on the bridge of the Blackbolt. Useful for providing translation services for the different cultures which intersect on the ship and also for interfacing with the droid staff. Also usfeul for calculating odds of success.
R2-D2 - One of several astromech droids that perform hyperspace calculations for the Blackbolt. R2D2 is something of an anomaly and provides better, faster routes than his other droid friends
General Tarkin - A weary but essentially good General of the XXXX system that wants to see an end to the series of wars that have been all he has ever known and have consumed his life time.
Palpatine - (to be revealed in the story section)
Owen Lars - Maybe he appears. Maybe not. Young and full of hope for his moisture farming.
Sort of Returning Characters
Valeria Organa - Princess of Alderaan, sister of Bail Organa. (Bel Dona if she needs another last name)
Darth Vader - Not Darth Maul, but some kind of armored Dark Jedi who is the right hand man (but not sole servant) of Palpatine. (Bash)
Mandalorians - The Mandalorian soldiers (13 maybe?) who are working for Palpatine. Use disintegration weapons.
New Characters
Sol Skywalker - ?? - Anakin's long lost Jedi father. Nik wants to find out what happened to him and become a Jedi like he was. Perhaps he is the Jedi that Ben served with in the previous Clone War which recommended he go study with Yoda. That would give Ben a stronger connection to Nik.
Blackbolt Captain - E1/? - Naval Captain of the ship that Obi-Wan and crew are stationed on.
Dark Jedi
Sem ???/Deak - E2 - A mysterious young Dark Jedi who is in the camp. Nik comes to respect him since he sees he lives under some sort of code. He is the Sith. He and Nik form an understanding and respect each other.
Sarm ??? - E1/E2 - A Dark Jedi Acolyte who is first seen briefly at the end of Ep1. He is a leader over the training pit at the DJ camp in E2. All muscles and cocky with power. Like a cliche drill sergeant. He personalizes the torture/conversion of Nik and is eventually killed by him.
Talia - E2/E3? - Concubine of the Dark Jedi Sarm. Nik is attracted to her and eventually becomes her lover once he defeats Sarm and claims her. She becomes pregnant with his child- is she the mother of the Skywalker children? Killed by Obi-Wan/his squad.
Soldiers
Kim'bal Shan - E1/E2/E3 - A Twi'lek who has joined Obi-wan's mixed company. He is a Jedi that is eager to join Obi-Wan once he is revealed. He is stoic, quiet and dedicated. Sort of a Tott Doneeta for these films.
Bike Arraton - A Corellian soldier that is in Obi-Wan's company. He is not a Jedi and at first he is very negative towards them. When he finds that his Captain is, in-fact, a Jedi, it wears on him for a day or so and then he lets it change his opinion of the Jedi for the better. Think of Hicks from Aliens. Eventually becomes captain of the squad when Obi-Wan raises through the ranks.
Bash ??? - A soldier
West - Another soldier in Obi-wan's company. From Obi-Wan's home planet. Heavy weapons.
Hamill - Another soldier in Obi-wan's company. From Obi-Wan's home planet. Recon.