Objective Section:
Qt4 is available with a GPL licence on *all* platforms. GTK+ is LGPL.
Subjective Section:
Unless we are working with some kind of "sins of the father" model, we should just stop attacking KDE based on Qt being non-free at some point in the past. This is just too tedious. The company has been very nice to the community, and the cooperation is ever increasing. You don't hear too many people attacking GTK for being LGPL.
Even more Subjective:
I believe that KDE was behind GNOME in terms of looks. Not anymore. If you like clearlooks in GNOME (the current default), try out QtCurve for KDE. It gives the same look and feel to the widgets. Similar color themes can also be installed. KDE is much more customizable than GNOME, and can be made to look and behave like GNOME, if you like it that way. As far as iconsets go, oxygen (shown at akademy 2005) is very beautiful! With projects like Tango, you could get similar iconsets for KDE and GNOME anyway.
The best part of KDE is the technology. It feels like a well integrated set of components, each excellent at its job. Unix philosophy extended to the desktop. I just love the ioslaves, kparts, dcop, and nx technologies. Ioslaves provide features like excellent network transparency. Fish protocol is godsent. Excellent use of kparts in kontact. I can right-click on a postscript file, and select an action, which would convert it to a pdf file, and upload it to my remote server over ssh. (No, kfmclient is much more general purpose and powerful than gnome's remote folders. And ioslaves are used more consistently than gnome-vfs). Dcop makes it easy for the user to do stuff like link his superkaramba themes (like gdesklets in gnome) to his music player or chat client. It is trivial to, say, take an incoming message from kopete (chat client) and make ktts speak it out over your speakers. (Not that you want to do that, but you could, with 10 lines of code). Some other features are given here: http://wiki.kde.org/tiki-index.php?page=KDE+Power+Features http://wiki.kde.org/tiki-index.php?page=Scripts+with+a+KDE+Feel
The upcoming technologies in KDE are even more exciting. Plasma is nice, and Tenor, a highly innovative project related to tracking context of data on your computer. It is far more ambitious than beagle / spotlight / winfs kind of projects.
I guess my point is, KDE is an excellent and exciting project, and if you haven't tried it out recently, give it a try. The real fun starts when you customize KDE with your own cute little scripts! I was a cli / KDE user, switched to GNOME with 2.6, and now back to KDE with 3.3/3.4. I try to track the progress of both the projects.
Cheers,
Bala.