The development on KDE 4.10 is is on full swing (we have created a KDE 4.10 update page) and today the KDE project leader Aaron Seigo announe that the upcoming release of KDE will change how window grouping is handled in the task manager.
Currently multiple windows are grouped together in the task manager and this is indicated by a black arrow and a small number showing the number of multiple windows open.
In keeping with the goal to simplify the appearance across the KDE Plasma desktop, Seigo reached out to the community to get a feel for what users want and expect from window grouping. An overwhelming majority mentioned that it's significantly more important for them to see that there are multiple windows grouped together rather than to see how many were being grouped together.
Many noted that knowing there is a group of windows just by glancing at the task bar is important to them. Very, very few find value in the little number, however. So putting it all together, in 4.10 a small arrow will be shown drawn over the window icon when there is a group, as is seen in many other dock apps. This preserves the most useful information while also limiting visual noise, creating a more compact layout in the window listing and finding consistency with other implementations out there in the wild.
Based on this feedback the KDE team has decided to do just that, group windows together and indicate this with an arrow (this arrow has also been updated from being a black arrow to being the standard oxygen-like arrow used throughout KDE) without the number indicator.
This update, albeit a small change, is a great example of how community input is still a driving factor in the direction of large open source projects like the KDE SC.