The complete sequence of actions
sudo add-apt-repository ppa:alexx2000/xfce
gedit /etc/apt/sources.list.d/alexx2000-xfce-maverick.list #in the file change the word maverick to lucid
gedit /etc/apt/sources.list.d/alexx2000-xfce-maverick.list.save #in the file change the word maverick to lucid
climb synaptic -> settings ->repositories check in the other tab AT the stand over the show is not officially supported updates in the Updates tab, I tick are everywhere. close settings repositories.
Click "update all packages then, in the search cinetica trying to drive xfce. poking xfce-utils from the top menu bar click package -> specify the version to select 4.8. On this package a pull for the upgrade to 4.8 version of all required packages -> agree and click the apply button, wait and rejoice.