Siliconera was lucky enough to get their hands on a Soul Calibur IV demo and try out the Star Wars characters in the game, and so what follows is a brief rundown of the main "features" and moves of each character.

Several features, however, are shared amongst all three characters. For one, the second meter underneath the character's life bar is linked to their force powers (Force Meter, perhaps?). Two, despite the armor breaking system, the SW characters take "battle damage", but don't have any dramatic effects or scars like the other characters (i.e. you can cut parts of their clothes off), meaning you can't knock off Vader's helmet, for example. But hey, who really wants to see that feeble crusty old white mug, anyway?
 

Darth Vader
 
Moves: choke, powerful unblockable burning force punch (VADER PAUNNCH!!)

Note: Using either of these moves without an adequate amount of force power will result in you being stunned.

Darth Vader’s Secret Apprentice

Moves: force levitation, fast lightsaber strikes

Yoda

Moves: Force Cancel (a temporary glowing green shield that stuns enemies when they attack, kind of like Blanka's electrical discharge), jump attacks

Sadly, custom made Jedi Knights aren't available in the creation system, and the 'classes' from it are gone; created characters have 'cloned' fighting styles, from the already available characters. Bonus characters like Angol Fear (pictured below) are clones too (many clones).

A demo for the game is planned, but not until after it's released. Some smart marketing, there.