OK, all went ok.

The only problem I had was PostgreSQL upgrade that didn't succeed.

I used the newly released postgresql-upgrade-9.3.5-2.fc20.x86_64 and not the version referred inside the bugzilla entry.
I don't know if it was part of the problem.

[root@tekkaman Downloads]# postgresql-setup upgrade
Upgrading database: failed

See /var/lib/pgsql/pgupgrade.log for details.

[root@tekkaman data]# cat /var/lib/pgsql/pgupgrade.log
Performing Consistency Checks
-----------------------------
Checking cluster versions                                   ok

*failure*
Consult the last few lines of "pg_upgrade_server.log" for
the probable cause of the failure.

connection to database failed: could not connect to server: No such file or directory
    Is the server running locally and accepting
    connections on Unix domain socket "/var/lib/pgsql/.s.PGSQL.5432"?


could not connect to old postmaster started with the command:
"/usr/lib64/pgsql/postgresql-9.2/bin/pg_ctl" -w -l "pg_upgrade_server.log" -D "/var/lib/pgsql/data-old" -o "-p 5432 -b  -c listen_addresses='' -c unix_socket_permissions=0700 -c unix_socket_directory='/var/lib/pgsql'" start
Failure, exiting

Digging  more in log files I saw:
-----------------------------------------------------------------
  pg_upgrade run on Thu Nov 13 00:18:11 2014
-----------------------------------------------------------------

command: "/usr/lib64/pgsql/postgresql-9.2/bin/pg_ctl" -w -l "pg_upgrade_server.log" -D "/var/lib/pgsql/data-old" -o "-p 5432
-b  -c listen_addresses='' -c unix_socket_permissions=0700 -c unix_socket_directory='/var/lib/pgsql'" start >> "pg_upgrade_se
rver.log" 2>&1
waiting for server to start....LOG:  SSL is not supported by this build
LOG:  SSL is not supported by this build
LOG:  SSL is not supported by this build
FATAL:  configuration file "/var/lib/pgsql/data-old/postgresql.conf" contains errors
.... stopped waiting
pg_ctl: could not start server
Examine the log output.

After removing from postgresql.conf the line

ssl = on

I was then able to upgrade PostgreSQL and continue with the other steps.

The Hypervisor part was fulfilled by the os upgrade itself.

BTW: in f19 I had iptables and not firewalld and this kind of configuration was kept in f20 too by the installer.

Gianluca