Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
Few major pieces of free software are more eagerly awaited than KDE 4. With changes to everything from the core libraries and window manager to the look, feel and function of the desktop, by any standard, KDE 4 is an extreme makeover of the popular desktop environment. Scheduled for release in October, KDE 4 can be toured now in the first beta that was released at the start of August. Taking the tour, the number of areas still under construction is obvious, and crashes are numerous, but enough is completed for users to get the first sense of what the final release might be like. On the way, you'll find major overhauls of general functionality,as well as both major and minor refitting of familiar KDE programs and the introduction of a few new ones.
Hardcore users can compile the beta from source. Alternatively, in some distributions like Debian, developers can download selected packages with which to code. However, at this stage, non-developers can make better use of their time by downloading one of the Live CDs/DVDs provided by such distributions as Kubuntu, Mepis, or OpenSUSE, or Gentoo.
Some of these live disks differ in content and functionality from each other. Some, too, seem a compromise between being functional and acting as a demo -- the Mephis disk, for example, provides KDE 4 if you log into the user account, but an earlier, stable KDE version if you log in as root. Moreover, booting from a DVD, none can give any sense of the speed of KDE 4. Still, any one of them should be enough to satisfy your curiosity, especially if you first read KDE's guide to the new features or Troy Unrau's "The Road to KDE 4" so you know what to look for.