Here's an interesting link that touches on Open AL support for mac games. Open AL will be needed to exploit the capabilities of soundblaster for Mac. It promises better sound (3d surround) and framerate improvements due to the soundblaster taking over audio processing and lessening the CPU load.
UT is already patched for Open AL..the patch will be released as soon as the card is available!
http://www.xlr8yourmac.com/stories/S11127.html#storytop
(Ca$H, don't fret, I've already got the ice pack out.)