Default terminal in GNOME 3

[Christoph Wickert]

I wondered how to set the default terminal in GNOME 3. The internet
revealed

gsettings set org.gnome.desktop.default-applications.terminal exec <terminal>
gsettings set org.gnome.desktop.default-applications.terminal exec-arg "'-e'"

This raises 2 questions: 
     1. Will it be possible to set the default terminal again in GNOME
        3.2? 
     2. Where is 'exec-arg' arg coming from? In the past we had the xml
        files in /usr/share/gnome-control-center/default-apps/ which
        contained an 'exec-flag'. How can I as a maintainer of several
        terminal applications let people know the proper
        exec-flag/exec-arg?

Regards,
Christoph