So, at some point, my X11 server in FC stopped accepting connection on the "default" TCP port, 6000. This wasn't a big deal until I started running another Linux distro in a VMWare VM (thanks VMWare for giving out free "enthusiasts" licenses a while ago!). Anywho, I did some poking around, and realized that gdm has changed it's default setting for listening on the TCP port.

I quickly edited /etc/gdm/custom.conf, and changed

DisallowTCP=false

After restarting gdm (and X11 obviously), everything is working fine again.