will not see the light of day for a few more weeks still, but the first features for Fedora 13 are now known. On the Fedora Project Wiki is now the Fedora 13 feature list
Added so far to the Fedora 13 feature list are mostly the few features that didn't make it in time for Fedora 12: NFSv4 protocol by default, support for mounting NFS servers over IPv6, and yum language package plug-in. Fedora 13 is also slated to pickup DisplayPort support for NVIDIA and ATI hardware via the Nouveau and Radeon drivers, respectively. Fedora 12 has already picked up DisplayPort capabilities for Intel hardware.
Look for more information on Fedora 13, which will be released around May of 2010, once Fedora 12 has made it out of Red Hat's offices.