So last week we had the auto-resize dock, this week we thought Fabounet was going to spend the week fixing the related bugs* but no instead he decided to implement a new function to the dock. This one was long awaited though (isn't it Mav )...
So if you recently updated your SVN version you must have noticed something...Yes your application have disappeared from the task bar. Actually it is just that the task bar, the applications bar as well as the applets bar have somehow merged.
So there are several new features :
An applet can take control of an application (which then disappear from the dock) : Rythmbox, Xmms.
A launcher can do the same (config option).
There is an indicator that appears below the icon which just stole an application (as well as under its sub-dock if it is in one)
The indicator is set by theme so you can really do what you want with it.
A launcher/applet controlling an application inherit its capacities: action on the window, transparency while minimized, activation animation, sub-dock in the case you have many instances of the same application, etc...
And if you wonder how to launch several instance, try SHIFT+Click.
Finally if you are not controlling an application from a launcher or an applet you can set it to use the icon of your launchers rather than the one provided by X.
Not convinced? try to launch Nautilus with and without the option!
As usual everything is highly configurable for a better experience (see for the options in the Taskbar tab of the configuration panel to tweak them)