Here is how it install KDE 4.5 in Ubuntu 10.04 Lucid Lynx system.

Step 1. Add the Kubuntu-ppa backports repository and then update the repository listing.

$ sudo apt-add-repository ppa:kubuntu-ppa/backports
Executing: gpg --ignore-time-conflict --no-options --no-default-keyring --secret-keyring /etc/apt/secring.gpg --trustdb-name /etc/apt/trustdb.gpg --keyring /etc/apt/trusted.gpg --primary-keyring /etc/apt/trusted.gpg --keyserver keyserver.ubuntu.com --recv E4DFEC907DEDA4B8A670E8042836CB0A8AC93F7A
gpg: requesting key 8AC93F7A from hkp server keyserver.ubuntu.com
gpg: key 8AC93F7A: "Launchpad Kubuntu Updates" not changed
gpg: Total number processed: 1
gpg:              unchanged: 1

$ sudo apt-get update

Step 2. Install kubuntu-desktop package.

$ sudo apt-get install kubuntu-desktop

Durning the installation you will be prompted to either use GDM or KDM as your login manager. It is totally up to you as to which one you pick. You will be able to get to either Gnome or KDE with either.

Sit back and relax and in a short time you will have latest version KDE installed along side your Gnome desktop manager.

I have an Asus 1005ha netbook running Ubuntu 10.04 and last night I decided to install the lasted beta version of KDE 4.5 from the Kubnutu Experimental PPA on it.  The upgrade was very smooth but then again apt-get installs rarely fails or cause headaches.

Here  are the issues that I have come across.

1) KDM will show the login screen but will not login to either KDE or Gnome.  When you do login you are just presented with a terminal, thats it.  Kinda reminded me of the old days.  I haven’t really looked in to this issue because I just when back to using GDM instead.  I will have to tackle this here in the coming nights.

2) The process called virtuoso-t consumes way to much processor.  Some where in the neighborhood of 50-80%.  Whats worse is that after some Google searches it seems that this is a carry over issue from 4.4x series.  I really hope this gets fixed.  I was able to kill that process and then the processor drop to consuming a normal 3% or less.

3) Tweetdeck.  Yes I realize that this is not a KDE issue, but for some reason when I opened Tweetdeck there is an extra small blank windows that opens in the top left corner.  This windows also takes a place in the task bar, which might not seem like a big deal except that I am running a netbook and screen real estate is expensive.  I am still looking in to this.  Also Tweetdeck consumes way more CPU with KDE than Gnome so for the time being I switched to Gwibber to tweet with.

4) I love the transparent start menu and systray pop-ups but if you have a white window open behind them they are almost impossible to read.  This is an easy fix with them changes or modifications.

As for KDE itself.  I think after 5 revisions of the KDE 4 series I am finally drawn back to KDE.  Thank goodness because I felt like such a trader after using KDE since 1.0.  The desktop effects are awesome and very smooth even on my netbook.  I don’t want to say who is copying who but I have been using Windows 7 at work and some of the KDE effects are very similar to it.  For example being able to drag the window to the side of the screen to tile or maximize it or as you hover your mouse over the application title along the task bar it pops up a small window displaying that application.  But KDE has added many other windows effects goodies that blow Windows’ Win-Tab effect away.

There are many other little fixes and goodies stashed throughout this release.  I highly recommend this version of KDE once it is released in a few weeks and hopefully it will not disappoint you and will draw you back to the KDE project.