This is just marginally about KDE4.4. It involves most of the packages in the repo, as Tex explained here:
The original plan was to simply update 2009 through 2010. Due to the complex issues and user intervention required to go to new kernel 2.6.32.4, udev, hal, initscripts, plymouth bootsplash, speedboot, xorg, compiz 3D, nvidia/fglrx drivers, ext 4 default file system, KDE 4.4 it is easier for me to provide a new ISO with a 2010 repository in a couple of weeks than to spend 3-4 months trying to work up some kind of valid upgrade path that probably be more trouble to the end user than it is worth. Once we get everyone on 2010 we can keep rolling along with updates again.
The root partition will definitely have to be formatted and installed. This is where a separate home partition comes in handy.
I personally will also delete the
.kde4 folder in my home directory and set up all I need again, but it actually shouldn't be necessary. Of course it always depends on how much effort is required to get back to a working environment one is accustomed to.
I hope this helps understand the process a little more

Torsten