I'll try to update this OP as info is released, but don't hold me to that.
Mesmer: Chronomancer
Guardian: Dragonhunter
Warrior: I've seen/read nothing concrete regarding warrior.
Necromancer: Reaper
Elementalist: Tempest, with current datamining hinting at main hand sword as new weapon
Engineer: No idea on the name, but based on the HoT announcement trailer, hammer will be the weapon.
Ranger: Druid, and staff as the weapon, per HoT announcement trailer.
Thief: Same as warrior currently, haven't seen anything concrete.
Revenant: I barely know much of revs to begin with.
General question I've been thinking but haven't seen an answer for: Will the new weapon combos require said specialization to be selected in order to use them? I would think and hope not, although I fully expect the elite profs to offer weapon perk traits (like reduced cd on weapon skills) for the new weapons.
Even though the elite professions are tied to HoT and it's release, who's to say there won't be more elite profs introduced in the future.