Creative announced the Xmod, which uses Creative's X-Fi Xtreme Fidelity audio platform to improve music playback quality for MP3, WMA, iTunes or AAC songs to beyond the original CD quality.

Update:
Creative Xmod Review Round-Up

Sounds like a magic device. French site GenerationMP3 already had the chance to test the Xmod.
I could not really determine in the review, if the resulting sound is awesome or not. I guess it will feel as adding more depth and volume to the sound.

Technically the Creative Xmod enhances the low and high frequencies while improving audio dynamics for cleaner, richer sound that surpasses the original audio CD. X-Fi Xtreme Fidelity provides two important audio functions, X-Fi Crystalizer and X-Fi CMSS-3D, which improve and enhance music listening experiences. The X-Fi Crystalizer upconverts MP3 music by analyzing and identifying which parts of the audio stream have been truncated or damaged during compression.

The Creative Xmod will be available in October at a suggested retail price of $79.99. Amazon.com has the Creative Xmod available for $72.95.

More details in this Creative press-release.