Korneliusz Jarzebski, the autor polishlinux has posted a neat article on visual changes in KDE 4.1. Amongst new features include an option in the taskbar to Show tasks from the current screen only, ability to resize Kickoff menu. Kwin also gains the Coverswitch effect, which is a visual effect similar to Cover Flow in Compiz Fusion and in MacOS and one of the neatest effects, I might add). Marble, the geography app also gains a new view & the maps can be watched using Globe, Flat and Mercator views. Amarok in particular has gone through some visual and backend changes. The default and non-changable backend is now Phonon.A new Plasma applet, the one displaying the information obout currently performing artist basing on Wikipedia has also been added.
Watch the screenshots over at polishlinux