However, to get these effects on a KDE or Gnome desktop, you must* use a 3D-accelerating hardware driver for your video card. Most video cards are produced by NVidia, ATi, and Intel, but of these three, currently only Intel has advanced Free/Libre/OpenSource drivers, used by Xorg in your system the moment X is installed.
If you have a computer with a built-in Intel video 'card', your 3D graphics and the effects that you see in those videos should work out of the box after installing a modern Linux distribution. Debian Sid with KDE 4.2 works great on my EeePC 701, for example, without any extra work on my part.
If you have an NVidia or ATi card, however, life isn't so easy. The *buntu people have Envy which assists with installing a closed, proprietary driver, but it's not perfect. As I am not interested in running *buntu, and it has failed for me in the past for Debian installations, I have to pass on this one.
The point is, installing these closed GPU drivers on one distribution or another is filled with occasional successes and (more often) failures. I have to say, NVidia seems to work a lot more often than ATi driver installations, and I maybe should have bought another NVidia card when I recently upgraded. I went with an ATi RadeonHD 3450, however, because of the lure of Free Software drivers....
Free Software drivers are in the works for both ATi and NVidia cards. ATi has released documentation since their purchase by AMD, leading to the FLOSS drivers 'radeon' and 'radeonhd'. My card, an ATi 3450 that I purchased with the express intent to use the radeonhd drivers, isn't yet supported for 3D but support for this functionality is in the works. See its progress here:
http://www.x.org/wiki/
Unfortunately for all Free Software users, and especially for the developer himself, Novell has layed off Luc Verhaegen, so that is one fewer developer working on getting 3D Acceleration in the RadeonHD drivers. The RadeonHD page once said to expect 3D Acceleration in the RadeonHD driver in 2009 Q1, which is now; this has since been changed with the loss of a developer and the 3D support is in development.
Likewise, for NVidia cards there is a FLOSS driver being written, named 'nouveau'. This driver is expected to be the default NVidia-hardware driver in the next Fedora release, warts and all, while its developers try to iron out its issues. Red Hat recently hired another developer to work on this driver, which is excellent news.
This driver also has Feature Matrix of its progress, available here:
http://nouveau.freedesktop.
As Desktop Linux and Free Software both grow in use, open and unfettered hardware access for driver writers is essential. For years, FLOSS supporters have written and campaigned both NVidia and ATi hardware manufacturers to open their drivers, and for years we've been shot down. Now the Linux community, including Novell and Red Hat, are taking matters into their own hands by writing the Free drivers instead of getting the drivers Freed from the corporations.
Unfortunately, this lets NVidia off the hook somewhat. ATi released the documentation to assist with writing this driver, but NVidia will get great graphical performance on their cards without helping the FLOSS community in any way.
This is the reason that I bought the ATi card, even though I knew my closed drivers installation would be difficult (I've given up), I also knew the Free drivers were coming and I wanted to support the company that supports the community.
* Enlightenment DR16 and Enlightenment DR17 both do not need 3D-enabled Graphics drivers to do some of their amazing desktop work. However, using these window managers is less common than KWin, Metacity, or Compiz.
