However, the desktop panel is the place where KDE 4.2 sports the most changes. The sole exception is the menu, where the restrictive Kickoff remains the default, although you can still replace it with the Classic menu or with Lancelot, if Lancelot is included among the widgets in your distribution. But elsewhere, the panel has become far more configurable.
To start with, panel settings now include controls for the screen edge and height -- characteristics that you could change in earlier KDE 4 releases, but that users had no indication existed. Just as important, a More Settings menu has been added to the panel settings display. From this menu, you can maximize the panel length with one item choice, instead of dragging on the easy-to-overlook arrows for resizing, or chose the alignment for the panel.
New options in the menu include settings to autohide the panel, or to allow other windows to overlap it, so that you can maximize screen space -- an option that is particularly useful if you have increased the height of the panel for easier reading.
Other improvements include better control of how widgets are added to the panel. In at least some distributions' versions of 4.1, some widgets -- the Calculator, for instance -- spilled out over the desktop rather than adding a small icon to the panel. Now, in 4.2, that has been corrected, and all widgets are added to the panel in a consistent and suitable way.
In much the same way, notifications and messages appear in a more consistent way, displaying just above the system tray in contrast to earlier releases, in which some messages caused confusion by appearing in other places.
On the task manager, which displays open windows, KDE also adds options for adding multiple rows and grouping when you have lots of windows open. You can now stack applications in as many rows as you choose, or group them automatically by program name. In addition, you can list all the contents of the task manager by desktop or alphabetical order, or manually or not at all.
The system tray has also changed, adding the ability to hide icons. Mercifully, this ability is not run for you by the desktop, as it is on Windows, but instead is a feature that you can configure as you please, either to save space on the panel, or else to ignore tray contents that you are not particularly interested in. You might, for example, prefer to hide the update notifier if you prefer not to be bothered by notifications of new updates.
Right across the panel, you find much the same as you do on the rest of the desktop -- more power, more control, and more ease of use.
If you were a KDE 3.5 user, you might not be very impressed by these new features. Many are neither impressive nor innovative -- and, after all, you had most of them before you started using KDE 4.0. However, as you use KDE 4.2, you may find that the cumulative effect is that, for the first time in KDE 4, you are working the way that you prefer, instead of adjusting your habits to the limits of the desktop.
That's not to say that KDE 4.2 couldn't use a tweak or two. Users could more easily find alternatives to the KickOff menu like Quick Launch if they were added to the main menu's configuration choices, instead of buried in the list of widgets. Similarly, some users might appreciate the ability to change the panel background without searching for the way to change desktop themes, or to move the panel to the top edge of the screen without obscuring the desktop toolkit (or "the kidney bean," as I have heard several users call it). But, in general, 4.2 is a major improvement that should leave most users generally satisfied, and wanting only minor additional enhancements.
The KDE Project has had a rocky year since KDE 4.0 was released. It has faced a barrage of criticism, some of it justified and much of it not -- and some unfairly abusive, no matter how valid. But, with the release of 4.2, the pressure should be off. KDE can still use additional enhancements, but, after KDE 4.2, almost all of the criticism is going to sound increasingly petty and spiteful.