Hello Linux Geeksters. As you may know, the Canonical developers have been working a lot at their Ubuntu 14.04 Trusty Tahr, lately.

Now, they are implementing fixes for the issues that occur when the users upgrade from old Ubuntu 12.04/Ubuntu 12.10 to Ubuntu 13.10/Ubuntu 14.04.
According to the mailing lists, only one test has passed, in the upgrade process verified on desktop, server, i386 and amd64.
As a reminder, Ubuntu 14.04 Trusty Tahr will be released on the 17th of April, 2014. From that date on, the Ubuntu users can easily upgrade to Ubuntu 14.04 via command-line.
First, get all the packages of the system up to date:
$ sudo apt-get update
$ sudo apt-get dist-upgrade
Upgrade the system, via the GUI:
$ sudo update-manager -d