I'm guessing that's because there's nothing new in KDE so that it can be considered a feature. They don't mention gnome either, even if it's the default and preferred DE.
They mention Gnome Shell which is something quite different and new that deserves/attracts attention.
Some preview of gnome-shell was already present in F12. And sugar spin isn't new either. Well, it doesn't really matter, but still, I'd like to see some more attention paid to present Fedora as "KDE distro" too.
Yeah, gnome-shell was/is present in F12 the same as python 3 for example, but they weren't considered ready to "push to the front" and be advertised as features.
F13 is running KDE 4.4, which I've heard is actually a significant improvement. Not as big of a deal as 4.2 -> 4.3, but still worth noting.