This week, of course, marked the debut of SoulCalibur on XBox Live Arcade, and it's more or less as awesome as you remember.
The version on sale is allegedly a port of the Dreamcast game. However, it's pretty heavily emasculated. Everything's unlocked from the moment you boot the game, and the available modes have been stripped down to Arcade, Versus, Time Attack, Survival and Museum. So you're getting a pretty basic experience for your $15.
It's also lame that multiplayer is restricted to local matches; getting your game on with players over XBox Live is not an option. Plus you'll be handling the whole thing on, naturally, a 360 controller, also known as "the controller not designed for fighting games".
However, none of that changes the fact that the core gameplay is extremely tight. SoulCalibur is a king among fighting games, and it compares extremely well to contemporaries such as Tekken 3. The controls are responsive, the commands are intuitive, and the results of gutting your opponent with a katana are as satisfying as ever.
Ultimately SoulCalibur is such a good game that paying $15 to buy an amputated clone of it is still an excellent bargain. This is one of the better games on Live Arcade today and worthy of your attention, even if just to tide you over the three weeks until SoulCalibur IV.