KDE 4.1 was released at the end of July 2008. This is a significant milestone for the KDE 4 series and for KDE in general, but as an early release in the KDE 4 cycle, it does have some known issues which will not be fixed in KDE 4.1. Huge progress has been made in KDE 4.1 which is listed in the KDE 4.1 Feature Plan.
Some of the more obvious issues are listed below. If these issues are important to you, you should stay with KDE 3.5 (KDE 3.5.10 was released in August 2008) until KDE 4.2 is released (scheduled for release in January 2009) when most of these issues are scheduled to be resolved.
It is possible that distributions will work around some of these issues before distributing to users.
Users of NVidia cards with the binary driver provided by NVidia might suffer from performance problems in window switching and resizing. We've made the NVidia engineers aware of those problems. However, no fixed NVidia driver has been released yet. You can find information on how to improve graphics performance on KDE UserBase, although we ultimately have to rely on NVidia to fix their driver.
The desktop in KDE 4.1 will mark the start of some significant user interface changes. This is a step away from the way the KDE 3 desktop was designed, but everything possible on your KDE 3.5.9 desktop will also be possible on your KDE 4 desktop. For KDE 4.1, however, some features are not yet complete, but should be ready for KDE 4.2.
This page is under construction. This section could really do with some screenshots on the page. You can help by editing this page.
FolderView is a new technology on the KDE 4 desktop which allows more than one collection of icons on your "desktop". However, it can still be configured to behave much like KDE 3 did. See this blog entry by Lydia Pintscher for some more information on FolderView.
The following issues are known and are scheduled to be resolved in KDE 4.2:
Some panel issues can be resolved before KDE 4.2. Because of the modular design of Plasma, a new panel could be quite easily written with autohide functionality. This would likely be written by a distribution team or a developer on kde-apps.org.
Session management is not fully implemented yet, at least not as you're used to from KDE 3.5. Some of these features might get implemented in a 4.1.x release.
Some KDE 3 applications have not yet been ported to KDE 4. Most distributions still package KDE 3 versions of these applications with their KDE 4 desktop. Some notable applications which will not be included in KDE 4.1 are listed below:
Projects with a different release schedule than KDE4.
Project (Current Version - Final Release Date)
Krusader is an advanced twin panel (commander style) file manager.
Binaries are available for all three major platforms. The developers are looking for volunteers to help put together screenshots for visual changelogs.
Nightly builds are available through Project Neon.
An alpha release of 1.1 (the KDE 4 port) is forthcoming, but not yet released.
The KDE4 port is under way but requires major rewriting to support Phonon and other new features. No releases scheduled at this time.
KPlayer 0.7 is the KDE4 port of KPlayer that was released on the same day as KDE 4.0. KPlayer 0.7.1 is planned for fall 2008 and will include a KDE4 port of its multimedia library which still used KDE3 compatibility layer in version 0.7.0.
The KDE4 port of Basket is currently in a pre-alpha state.
The KDE4 port will not be released to sometime after version 1.1, which will be the last KDE3 release.