I'm neutral on the whole Prestige Class deal. Some are pretty weird (and way too specialized), but in Star Wars, I like the option that, for example, you have one base class like Jedi and you can span out to a Jedi Master or a Sith Lord depending if you want to be "good" or "evil". That's the extent I like them to be, but stuff like chopping up Jedi Master into Jedi Weapon Masters and Jedi Teachers etc. goes way too overboard.Me personally, I don't get prestige classes or multi classing at all, I've only used regualr (single) classes in all my games.
That said, I like the reduced number of base classes and the ability to specialize a bit using Prestige Classes, but I have my reservations that in Saga there are Prestige Classes for both Jedi Knight and Jedi Master in addition to the Jedi base class. That's got to cause some head scratching.
But I'll reserve any judgment after the book's out.