You may have a confusion of terms.
The distro is PClinuxOS
And the Desktop Environment (DE) is, KDE, Gnome, etc. etc.
As MaddogF16 said, these other DE's are maintained by community members, & rather than detracting from the distro's focus it greatly broadens it.
Each DE has it's own attraction, cosmetic & technically & has special appeal to a wide variety of people.
So I think most see our community remasters of many DE's as an asset. Many other distros are doing the same btw.
Anyway, have a good time with your PClinuxOS2010 in whichever flavor you choose!!