Well I just got the latest XP drivers from Creative's site and found that they finally integrated a few of those original bells and whistles, plus some I didn't see before.
In the EAX Control Panel there are a number of presets to choose from. This is where the "Chipmunk" and "Zeus" effects were in the '98 drivers, but in XP they had originally trimmed it down to just a few environmental 3D effects. But now they added back an "FX" section of filters that includes those Chipmunk and Zeus settings, plus some new ones: Karaoke Pitch (-4) through (+4) for changing the pitch of your music so it's in your vocal range, and Music Normalizer, which I think is an awesome idea. It normalizes the Wave and CD sources in the mixer so that they're at a constant volume... like how some TVs normalize their sound to cut down those loud commercials.