Isn't it a bit of a nightmare job to swap it out, involving the removal of lots of trim? Personally I would try and get an MP3 playing head unit, black fascia 2005 onwards.
Yep, I remember finding a guide on here for replacing the CD changer - very quickly put me off the idea of an MP3 changer
If you're after MP3 capability in the car it's easier going for a newer OEM headunit from approx Oct 2005 onwards (date mioght not be exactly right but it's around then they changed).
Correct you will not get ID tags with the factory headunit and changerusing MP3 Cd's, plug in a Dension or similar and you can get tags on factory headunit with Ipod