The only differences between this version and Fedora Core 1 are the presence of SELinux (a security policy enforcer), and a different UI.
This is the default desktop, with the new Clearlooks theme which was inspired by Red Hat. Here we can see the traditional Linux two-bar setup with the three menus at the top.
The menu arrangement is similar to that of Ubuntu 7.10.
Fedora still uses Nautilus to do the file managing.
It also still includes Firefox
Not sure what happened, but apparently there are no screensavers included by default.
Fedora Core 4 brings the Linux desktop we came to know before GNOME 3 came around to Fedora. That's about it, there isn't much else that's different from previous versions.