after a text install of solaris 11, here’s a quick way to get x & gnome up and running:
sudo pkg install slim_install
sudo svcadm enable gdm

also of note is that all current releases of solaris are 64-bit only…despite some releases still being listed as x86.

and…nice first steps article from oracle:
http://www.oracle.com/technetwork/articles/servers-storage-admin/o11-112-s11-first-steps-524819.html

source:
http://www.dai-mao.com/solaris/solaris-11-install-gnome