I have started the process of creating a Kryptonized version of the TreeView control. As with many of the Krypton controls in the Toolkit it works by using the custom drawing ability of the standard TreeView control. So it will not have any new functionality but should draw in a manner consistent with the rest of the Krypton controls.
So far I have implemented drawing the node text and the tree plus/minus nodes and lines. You can see two examples below, the first using the Office 2010 Blue palette and the second the professional palette.