Thanks to Bigon, the Ubuntu Telepathy team have now its own Personal Package Archives. We'll use it to store packages of the latest upstream version of the Telepathy stack (connection managers, Empathy, Farsight, Soylent, ...) that can't be included in Gutsy due to freeze.
So, if you want to be sure to have latest releases, you just have to add these 2 lines in your /etc/apt/sources.list :
deb http://ppa.launchpad.net/telepathy/ubuntu gutsy main restricted universe multiverse deb-src http://ppa.launchpad.net/telepathy/ubuntu gutsy main restricted universe multiverse