Best New KDE4 Feature

Plasma
plasma looks nice but in the other hand is extremly slow and hard to manipulate with, what would be maybe a good idea is to have some "snap zone" arround plasmoids !with options for switching it off!, and yet there are no useable ones, except of course the commandline executor, which cames handy when kwin crashes, but plasma crashes more often..

KWin with Desktop
how many of kwin efect you are using on daily basis? well, the expose is definitely big improvement the rest is simply useless cpu hog.

Oxygen Theme
nice! would be nice to have icon theme for KDE 3.5 as well since some applications are not yet replaceable by its alternatives from KDE4 (amarok, kaffeine)

Dolphin
I don't see any reason for dolphin and I am disappointed that konquerors' file-browsing capabilities regressed somehow. I also miss the great filelight view from Monsieur Howell of methylblue.com

Dragon Player
fullscreen doesn't work while in kontact, also as well as pause, maybe its because of a streaming content. somehow better than totem, not yet on kaffeine previous usability level.

Okular
this one is indeed a good one!

New KDE PIM
The best and only reason for KDE4.2 in my opinion, thank you!

New System Settings
this is getting better, what is still lacking are mouse gestures, they are not part of systemsettings anyway but I couldn't found where to put it.

General Cleanups
yes, its so very clean it could be hanged on wall, but not yet used.

Improved Usability
like what? all I see are mostly regresions, well yes, ocular and kontact are both big pluses, and krunner got some nice features as well, but I would prefer to have my gestures there, I am so lazy to use keyboard ;-)

Zooming Workspace
like the plasma zooming? whats that for anyway??!

Other
step makes me want to return back to school, this is very cool thing! good work!