Actually it’s 4.1, apparently more stable that the point release, and that’s why I waited as long as I did. For more instructions, see http://kde4.debian.net/. You probably need to upgrade to Lenny first.
Well, late to upgrade (or update) as usual, but the wait (to upgrade) to KDE 4 was well worth it, as there was only one small dependency issue which didn’t affect the boot into KDE 4.
Way to go! Text seem to render much prettier now, which is a good thing!