This should be a welcome surprise. Creative has released the source code for its Sound Blaster X-Fi and X-Fi Titanium Series Linux 32bit/64 bit drivers. Supported features are PCM playback, recording and mixer functions for ALSA

This download is intended for the following audio devices only:

• Creative Sound Blaster X-Fi Titanium Fatal1ty® Champion Series
• Creative Sound Blaster X-Fi Titanium Fatal1ty Professional Series
• Creative Sound Blaster X-Fi Titanium Professional Audio
• Creative Sound Blaster X-Fi Titanium
• Creative Sound Blaster X-Fi Elite Pro
• Creative Sound Blaster X-Fi Platinum
• Creative Sound Blaster X-Fi Fatal1ty
• Creative Sound Blaster X-Fi XtremeGamer
• Creative Sound Blaster X-Fi XtremeMusic

You can download it from this Creative forum announcement. From the looks of it, someone has already successfully used the compiled kernel module in Ubuntu 8.10.