Well other than me going home for the holidays today, I'm happy to announce that Songbird 1.4 is out! I have been waiting for this release for ages!
Anyhow, if you followed my guide to install songbird, and want to update, all you have to do is type in:
sudo rm -r /opt/Songbird
Then download the new version of Songbird and follow my guide up to step 2.
So run this command inside the folder where you downloaded Songbird:
sudo tar -xvzf Songbird*.tar.gz -C /opt/
sudo chown -R username:username /opt/Songbird/
Of Course substitute username, for your actual user name. That should be the basic install of the program, but if you want to add the extra features that I was talking about at the beginning of this tutorial, then go ahead and keep on reading.
This should do it, good luck and have fun!