To be frank, I'm not entirely sure why, but somebody has taken it into their mind to port Linux KDE4 applications to Mac OS X. As we've previously mentioned, KDE has been able to run using Apple's X11 Window System, but this new effort will be better integrated into OS X, including the use of Aqua. What this means is that the KDE Workspace (desktop environment) itself won't be ported, but certain applications like KOffice and Konqueror will. They will appear to run just like native OS X applications, with Aqua windows, etc.
The author mentions at the end of his article the advantages of bringing KDE applications to the other platforms. His main point seems to be that KDE users will benefit as developers on other platforms are exposed to the KDE Applications (e.g. Safari's underlying HTML rendering engine-Webkit-started out life as KHTML from KDE, so as websites have moved to support Safari better, Konqueror users have benefited as well). Perhaps it's just because I'm not that familiar with the KDE applications, but I'm just not really seeing how this benefits OS X users that much. That said, I guess I'll chalk this one up to more is better, and besides, it's a pretty cool technical achievement if nothing else. Let me know in the comments if there are any applications from KDE you're really looking forward to.
[Update: As usual TUAW readers are great. Thanks for all the app suggestions; now you've got me excited!]