In 9.04, Ubuntu introduced the ridiculous default of waiting 60 seconds after you clicked on “shut down” before actually doing it. Presumably in case you changed your mind. Yeah, really useful.
Upgrading to 9.10 re-introduced this “feature”, but it’s now even less obvious how to turn it off. Here’s how:

1. Press Alt-F2
2. In the Run Application window, type the following then click on Run:
   gconf-editor
3. In the Configuration Editor window, go to Apps/indicator-session, check the suppress_logout_restart_shutdown checkbox, then close the window.

Nice.