Some fine and obvious predictions have certainly been made. I don't think anyone could be too terribly surprised with any of the following: BB8, C3PO, Jedi Luke, Padme, Wicket, Jango...just to name a few.
But when we talk about the concept of "Fan Favorite," I think I can describe something that would quickly become a fan favorite of players of this game. As I have proposed many times, Jabba the Hutt! The slimy stud would be in the game with a chained gold bikini clad Leia. His special skill would be to sling the chained gold bikini clad Leia around in circles above his head and then do an AoE, smacking all of his opponents with her. This would quickly become a "Fan Favorite" for sure! If Jabba the Hutt is defeated, he doesn't just scream/yell and disappear from the screen! Well, he does....but Leia is released and joins your team as a 6th character...or she can just get released and run off the screen into the arms of Ewoks or something?! Anyway, we could certainly have some interesting things happen if Jabba the Hutt was introduced to the game. Other specials Jabba the Hutt could have?...puke on everyone, fart and gas everyone, slime everyone, eat someone, command bounty hunters in a special attack...
So, if we don't get some version of that, I would vote for Wicket but I don't see that happening so I would probably go for C3PO to have AWESOME synergy to make Ewoks 100% Arena Top 10 Viable like they were in February 2016!...then combine that with a re-work and zetas added to Ewoks...Teebo definitely needs to be a properly taunting tank. So many ideas, so little time.