Quote from Darth Hater on last two classes (Sith Inquisitor and Jedi Consular):
We talked a lot today about being able to customize your classes in a number of different directions. When you think of Sith Inquisitor, you’re thinking about how we’re talking about him today in the Emperor Palpatine mold, the force lightning using guy. But as time goes on, we will show you other ways to customize that class that will give you a different gameplay style. We thought as core classes the Consular and the Inquisitor made the sense. We thought they balanced well against the other two. You can think of the Jedi Knight and the Sith Warrior as more of a melee-style Jedi, and the other two maybe more of the ranged-style Jedi. I think it made a lot of sense.