I guess a roadmap would be useful. I'm sure there are plenty of people here who can code AngularJS (myself included), so can't we just code it collaboratively?
With some guidance of what needs to be done from whoever is in charge of this project maybe we could speed up the development.
Since it's on Github you can always fork it and I guess if someone ever manages to finish this piece of software then admin can change the DNS names like Reddit did and make new.bitcointalk.org point to the new forum software (and bitcointalk.org continues to point to the SMF version).