Hi Lerax,
I've seen something similar in syncfusion grid:
Infragistics and teleric also have something alike. While writing this I found one more controls library: DlhSoft Hierarchical Data Library. It looks like they have exactly what you want: TreeListView Control.
By the way, in VS 2010, it's not true WPF control. Snoop showed it's hosted inside some kind of HwndHost panel.
If you don't want to buy 3rd parties, you could write it yourself. I would start from TreeView, and customize TreeViewItem. To create columns I would try shared grid size scopes. On big data sets it will be slow though.
Hope this helps you start going.