I'm working on a laptop which triple boots. I've only got Logout and Suspend. I downloaded GNOME Tweak Tool, and there is no setting to offer reboot. So when I want to reboot, I need to open a terminal, su, and then reboot. Perhaps it would be a good idea to offer people with laptops and desktops a traditional Shutdown and Reboot. GNOME3 looks very good, but its clearly oriented for netbooks and tablets. Unfortunately, I don't have a SSD or FLASH storage in my laptop or desktop, so I will need to shutdown are reboot gracefully.
For discussion about this controversial decision by the Gnome developers: https://bugzilla.gnome.org/show_bug.cgi?id=643457 The option is actually there, but you have to press the Alt key while viewing the User Menu to see it. To get the "Power Off..." option by default, install the gnome-shell-extensions-alternative-status-menu package.
Forgot to mention that you have to restart Gnome Shell to see the new entry - either log out and back in, or run "r" (without quotes) from Alt-F2.
Thanks Andre. GNOME3 actually looks really good. In its current configuration, it would make a great desktop manager for my iPad or a tablet. But it sucks as for a host which is a classic desktop or laptop.
Closing - its by design....