As discussed in comment #9 through comment #16 of https://bugzilla.redhat.com/show_bug.cgi?id=855310 , anaconda in F18 Alpha RC2 does not seem to be respecting the 'optionlist' directive in comps.

As described in https://lists.fedoraproject.org/pipermail/devel/2012-August/170620.html by Bill:

"Each environment has a grouplist that lists the groups that make up this
enviroment - these are the required groups that will be installed if you
select this environment. It also has a list of options for that environment,
which are also groups in comps...Whenever an environment is selected in anaconda in the left pane, the right pane will be populated with:
- the list of options for that environment in comps"

i.e., when you pick a group in the left-hand pane of the package spoke, the groups listed in its 'optionlist' directive (if it has any) should show up in the right-hand pane of the package spoke (regardless of what <uservisible> is set to). This definitely isn't working in Alpha RC2, though. The list of groups in the right hand pane consists only of all groups with <uservisible>true</uservisible>, and never changes, whatever you pick in the left-hand pane.

I don't think this strictly violates the Alpha criteria, as the desktop groups themselves do at least contain enough packages to start the desktops and run a browser and a terminal and the software update app, which is all we require for Alpha. But proposing as NTH, as obviously we want people to be able to install a fully-featured desktop.