Upgrade KDE to 4.2

[Amila Liyanaarachchi]

Hi,

I'm a Kubuntu beginner, and curious to have KDE 4.2.
I tried the following to get it updated, but end up with the below
error. Can someone tell me what has went wrong here?

Added the line "deb
http://ppa.launchpad.net/kubuntu-experimental/ubuntu intrepid main" to
third party software list in apt.
gave the command "sudo apt-get install kde-nightly" which I found from
some site.

then I end up with the below error message,
--------------------------------------------------------------
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.

Since you only requested a single operation it is extremely likely that
the package is simply not installable and a bug report against
that package should be filed.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 kde-nightly: Depends: kde-nightly-kdebase but it is not going to be installed
E: Broken packages
-----------------------------------------------------

Regards,
Amila