http://www.guildwars2.com/en/the-game/professions/
Note that the image is revealing itself as professions are revealed.
That looks like a charr carrying a big gun in silhouette on the far left, so I assume that is the gunner class. It has been mentioned before in interview (always subject to change, of course) that there will be a class that can use only guns and one that can use bows but not guns (the already revealed warrior can use either, it seems), so that gives 'Gunner' and 'Ranger' (placeholder names) as two more to come.
Warrior is one of the two heavy classes- will one of the ranged classes take the other heavy spot, or will they both be Adventurers? A Gunner might make a good choice for the other heavy.
Meanwhile, rumour is still running rampant that Monks will either be absent or radically re-done. Here is a quote:
Isaiah Cartwright – Game Designer: Healing in GW2 is different from most other MMO's. One of our goals is that you should always be happy to see other players and this shouldn't change based on their profession, race, skill choices, or anything else. Which means each player needs to be slightly more self sufficient so that one particular profession is not required to do any given type of content. It's why we made the healing slot a required part of the skill bar. It allows us to make the heal skill powerful enough so players can take care of themselves. There will still be ways to support your allies and some professions will specialize in support but no single profession is always required.