Fedora Core 1/2/3 are all final releases .. but as what Redhat said, it is a community release and not one of their commercial products. If you're looking for a commercially supported product, you should go for REL releases.
There are quite a number of improvements done to FC3, SELinux, new GNOME, KDE and many new nifty stuffs to list the least.
Nope, no native NTFS and MP3 support. You need to go for 3rd parties for that.