From SoulCalibur.com:

I’m sure by now many of you have heard the rumors from Japan and I’m
here to say most of them are correct. Granted, I can never keep up with
everything people say so it’s impossible to confirm everything.
Soul Calibur III: Arcade Edition is a re-tuned, re-vamped, and most
importantly, fixed version of Soul Calibur III. Naturally, all glitches
found in the console version have been fixed. In addition to that,
we’ve re-tuned the overall balance of many moves and re-vamped Amy,
Hwang and Li Long as official characters. All three have been revised
into more unique move sets and help to expand the already expansive
Soul Calibur III line-up.

We expect Soul Calibur III: Arcade Edition to release within six weeks. Stay tuned for more information.