Comment 7 for bug 263442

The solution for using vi is to use the command: sudo update-alternatives --config editor
This will show the following (in 9.04 at least) from which you can change the default editor to vim:

There are 4 alternatives which provide `editor'.

  Selection Alternative
-----------------------------------------------
* 1 /usr/bin/vim.tiny
          2 /bin/ed
 + 3 /bin/nano
          4 /usr/bin/mcedit-debian

Press enter to keep the default[*], or type selection number: