Task Preview has been changed to panel-based on the recent revision (like the navigation panel on the side). Previously it was on the split view on task tab sharing the space with task grid. Now that it has been changed to Panel it can be accessed from other tabs too. It also much more flexible in term of layout. It can be docked to top or bottom or even just let it displayed as a floating panel.
Below is a screenshot of the new task panel :
Below is when it is floating (separate window) also showing is a placement guide when moving the docking target :