I hate KDE4, probably more than I should. No, definitely more than I should. For me the problem is that Konqueror used to be perfect, and now it's only great. And I just can't seem to get over that. If I could, my life would be a lot easier. The effort that I've put into hanging onto KDE3 (including releasing my own live CD) is way way more effort than occasionally having to step over the mediocre web browser to get to the greatest file manager ever, and maybe I would eventually stop getting mad when I have to leave Konqueror and go to Dolphin (which, contrary to the opinion of most diehard Konqueror fans, is not completely terrible.)
I've tried every KDE 4 release up to KDE 4.3.3, and it's absolutely true that KDE4 is... well, not completely terrible, either. Most of the plasmoids are either useless eye candy, or no better than the panel applets they replaced, but IMO just one plasmoid, the sticky notes plasmoid, is simple and practical enough to justify the whole plasma rigamarole, and i like the analog clock because having something round on the desktop breaks it up nicely.
Mostly, the problem i have with KDE4 is not something I can rationally explain or justify, but I don't feel that I should have to. It just just feels icky to me. Oh God, and setting it up is about as much fun as a colonoscopy. I respect that lots of people love it, but with hundreds of distros, there ought to be a place where we can go. The user base is out there.
Anyway, this is a good article, but I want to point out that most of the things you mention are available in KDE3. Did you know you can split the screen for Konqueror up like that? Hells, yeah! The terminal window in dolphin is nice, but Konqueror offers a simpler option that I prefer. Yes, there's a slideshow in KDE3, and in some ways it's more configurable.
KDE 4 is here, it's severe, get used to it. That was never in question., but there are people working to keep KDE3 alive as an alternative for debian-based user and for Slackware fans. Sorry no one is doing that for Gentoo.