Dusting this off, because I read something before SWCO that this project might still be in development.
The rumors I've heard say that this project may not just focus on Boba Fett, and it may actually feature a number of bounty hunters on some sort of mission. So it may be more of an ensemble kind of story. Will it get into some EU territory like the bounty hunters guild? That could make for some interesting callbacks to established material.
A story pitch that I'd like to see including the bounty hunters might take place between the events of A NEW HOPE and THE EMPIRE STRIKES BACK. Just how did the Empire learn the identity of the rebel who destroyed the Death Star? How did Darth Vader make that connection between the X-wing pilot he came close to shooting down during the trench run, and the son he didn't know he had? That might be a story worth telling that employs the bounty hunters.
Rumor also has it that the next anthology / spin-off movie may get announced over the summer. I would think that could be at either D23 or SDCC.