Fedora 17 now officially sets it’s memory requirement for installation to 512MB. Before Fedora 17, the requirements and been a similarly unrealistic 768MB. A standard desktop installation with Gnome 3 in tow will not be able to perform realistically for any user. Of course Fedora is good for a great many configurations, including different desktop environments and server configurations, but allowing the average user to complete an installation in the standard desktop configuration at such a low bar, seems like a strange move.