Among the new features, a few stand out, such as the First Aid Kit. It's essentially a rescue environment that can help fix a broken system by offering dmraid rebuild and recovery options, bootloader and initrd reinstallation and re-creation, and potentially even some base package reinstallation. In a pinch, it could certainly prove helpful.
Also, Fedora 10 includes sectool, which is a system-integrity scanning tool that can check the system for possible security issues by evaluating various OS components and comparing them against known-good states.
One oddity is the default addition of /sbin, /usr/sbin, and /usr/local/sbin to the normal user default path. Since the dawn of time, only root has included these elements in the default path, because the tools residing in those directories are generally for admins only, not normal users. In Fedora 10, every user's default path has them. Ostensibly, this is to eliminate problems with novice users who don't understand pathing and tool location, but I don't know that I see any real benefit, because normal users shouldn't need lsmod, mke2fs, and so forth.
The installation process -- generally the same as in previous releases, using the Anaconda installer -- is smooth and surprisingly attractive, offering support for encrypted file systems, ext3 and NTFS resizing, and fluid repository inclusion. Some of these features were present in Fedora 9, but are somehow better integrated into the new version. All in all, installing Fedora 10 is a very simple and straightforward process.
Following installation, the familiar firstboot process allows the creation of local users and post-installation tweaks. Then, it's a GUI login prompt and the introduction to the Solar theme. Gnome panels slide into place rather than just appearing, window corners are rounded, and the overall experience is attractive and polished. There's something different about Linux desktops today, and not just the menu layouts and other GUI elements; they just feel slicker, yet somehow more utilitarian all at once. Gnome 2.24 and the Solar theme are no different in this regard. One relative oddity is the "Leave Message" option when the screen is locked. This feature was introduced in Gnome 2.20 and allows someone to wake a locked system and type a message that will be displayed when the owner logs in.
As with any new distribution, Fedora 10 will undoubtedly reveal some rough edges. There will be some hardware issues, there will be some significant updates, and there will be untold discussion of this package and that kernel module on the forums and wikis. My exploration of Fedora 10 has been fairly straightforward, and so far, so good. I'm sure that I won't be running Fedora 10 on mission-critical commercial production systems, but I have been running Fedora on my main workstation and Linux laptop since FC1, and will be updating as soon as I can.