Please(Odoo devs or sysadmin person in charge of nightly.openerp.com) add verification for Odoo:

<pre>
apt-get install odoo
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following extra packages will be installed:
  antiword docutils-common docutils-doc fontconfig fonts-liberation graphviz javascript-common libart-2.0-2 libcairo2 libcdt4 libcgraph5 ....
Do you want to continue [Y/n]? y
WARNING: The following packages cannot be authenticated!
...
Install these packages without verification [y/N]? 

</pre>

You can find out more about adding the verifcation for your .deb packages here:

https://wiki.debian.org/SettingUpSignedAptRepositoryWithReprepro