Most of them make a re-appearance in Post-Searing in one form or another and will offer some more quests with skill reward for their profession.
There are 3 Profession Trainers for each core profession. For some professions there is another NPC to give you skills, but they are not a Profession Trainer per definition. Additional skill quests are available to earn skills later in the game, and can be found using the legend in the quests article.