Honostly? I dont think they will add any more professions. The eight professions we have all cover all these mentioned suggested professions in some way or the other.
Sure theres no shapeshifter archtype as such, but the mechanics of a shapeshifter is mingled with the engineer through kits.
Id personally like to see the "Death Knight" archtype, but playwise it would prolly come out as a mix of the Guardian and the Necro, hence it wouldn't work.
Now I do believe they will add more weapon choices to the excisting professions, and maybe a new trait line for each.