Most terminal programs today (example vim and ls) can take advantage of 256 color output. Increasing the color limit from 8 to 256 will definitely make it convenient for user to use these programs. Also, Mac OS terminals (version 10.7 and above) use 256 colors by default. This will make cross-platform compatibility problem free to some extent.
If you want to test how many colors your terminal supports, you can run the following command:
Fedora 18 is scheduled to be released later this year with new features like Gnome 3.6, InitailExperience, OfflineUpdates, a new package manager and more.