That section is out of date.
There's a debian/ which you can use to build debian packages for Debian/Ubuntu... someone will need to update it at some point
Assuming you checkout into a freeswitch directory, this should work:
$ cd freeswitch
$ (cd debian && ./bootstrap.sh -c squeeze)
$ dpkg-buildpackage -b
There'll be a ton of .deb files in the parent directory, which you can install with "dpkg -i filename.deb"
Stick all the ones you need in a single command and it'll keep the dependancies between fs packages happy.
-Steve