Brasero installs a "CD/DVD Creator" .desktop file which opens burn:// in nautilus. However, if nautilus-cd-burner is not installed, there's no way to actually burn the files as the blue bar with the burn button is missing. If nautilus-cd-burner is installed it seems to "take over" burn://, it does not matter if you launch the original or brasero's "CD/DVD Creator" .desktop
This should be fixed in rawhide. The problem was 'brasero-nautilus' not being installed by default. Make sure to install 'brasero-nautilus' and let me know how the brasero/nautilus interaction works now. The package 'nautilus-cd-burner' doesn't have to be installed. If it is, it will be superseded by brasero.
Seems to work fine now, thanks.