OK friends, KDE 4.0 is ready, as you can read here, and it can be downloaded from KDE FTP mirrors, but some distributions have already include it in their testing or something branches, or as Live CDs, if you want to see if yours is included check the bottom of this page

If some of our readers compiles it, or install it and want to share its experiences, please use the Forums to post them, and share with the rest.