Fedora is the community version of RedHat if I say in civilized manner. To be more rude I can say that Fedora is the bleeding beta version of RedHat where the community will test and fix the bugs for them before they release the next stable enterprise version. Actually when RedHat went from being free and opensource to a licensed OS, they created fedora to keep the opensource part of the OS active.
But, Fedora is the operating system which is closest to being a real opensource operating system compared to distributions like Ubuntu which has more commercial purpose.
If you have a look at Ubuntu which is my personal operating system it is now having some paid software appearing in the software center, which is an indicator of deviating from free and opensource mode. With time we will start to a see a radical deviation of Ubuntu to towards commercial side as far as I see. This will close up the doors or restrict the large number of users who have switched to Ubuntu. So I guess very shortly (within another few years time) the time will come to switch to fedora or some other Linux distribution. Fortunately most of these distributions use the gnome desktop environment, so switching will not be very hard. You can make the switch now or wait, but I can tell you that you will have to make that move sooner than later.